Undertow CVEs with no public exploit

53 CVEs, 4 protected by Waratek

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Overview 53 matches · 4 protected · 0 exploited · 0 CISA KEV · 0 public PoC · 0 EPSS ≥ 0.5

53matches 4protected7.5% 0exploited0.0% 0CISA KEV0.0% 0public PoC0.0% 0EPSS ≥ 0.50.0%

Protected by Waratek 4 7.5% Rule in development 0 0.0% Mitigation candidate 0 0.0% No exploit published 49 92.5%

Critical 4 7.5% High 29 54.7% Medium 20 37.7% Low 0 0.0% None 0 0.0% Unknown 0 0.0%

blocked by ARMR today 4 7.5% partly blocked 0 0.0% not blocked 49 92.5% not established 0 0.0% unrecorded 0 0.0%

Exploited 0 0.0% Working exploit published 0 0.0% Proof of concept only 0 0.0% Forecast only 0 0.0% No public exploit 53 100.0%

split by StatusSeverityProtectionExploit maturity peak 11 / year

2014201620182020202220242026

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CVE	Severity	Published▾	Status	Exploitation	Description
CVE-2026-78329	Critical	2026-08-24	No exploit published	No public exploit	Improper input validation vulnerability in Apache Camel Undertow component. This issue affects Apache Camel: from 4.11.0 before 4.14.9, from 4.15.0 before 4.18.4, from 4.19.0 before 4.22.0. UndertowEndpoint defaulted its headerFilterStrategy field to the base HttpHeaderFilterStrategy and pushed that instance into the UndertowHttpBinding it creates lazily, overwriting the UndertowHeaderFilterStrategy that DefaultUndertowHttpBinding installs in its own constructor. Unless a deployment supplied a custom binding or an explicit headerFilterStrategy, the undertow-specific filtering therefore never executed on endpoint-configured routes: the strategy object was constructed and immediately replaced before it could be consulted. The consequence is that the legacy websocket. Exchange-header prefix was not filtered at the undertow transport boundary in either direction, so an undertow HTTP consumer mapped inbound wire headers of that form onto the Exchange, where an undertow WebSocket producer reads them as dispatch directives and can be made to deliver to a peer other than the one the route selected; and header names that undertow itself does not accept were mapped onto the Exchange rather than being skipped. Rest DSL consumers were never affected, because UndertowComponent assigns UndertowRestHeaderFilterStrategy explicitly, which extends the undertow strategy. This is not a regression of CVE-2025-30177: the base HttpHeaderFilterStrategy configures the inbound Camel-prefix filter itself, so the protection introduced by that advisory continued to work through the base class and was never lost. What the change did was leave the undertow strategy orphaned on the endpoint path, with the effect that two subsequent corrections written into it - one skipping header names undertow rejects, one filtering the legacy websocket. prefix in both directions - were applied to a class the endpoint no longer used and never took effect in the releases that shipped them. Users are recommended to upgrade to version 4.22.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.9. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.4. For deployments that cannot upgrade immediately, configure the strategy explicitly rather than relying on the default, for example by binding an UndertowHeaderFilterStrategy in the registry and referencing it on the endpoint as undertow:http://0.0.0.0:8080/foo?headerFilterStrategy=#myStrategy, and additionally strip the dispatch headers at the trust boundary with removeHeaders(“websocket.*”). Note a residual limitation that upgrading does not remove: the undertow component deliberately keeps the websocket. values as part of its externally visible API contract, and UndertowProducer reads them with in.getHeader, which does not consult a HeaderFilterStrategy at all. The restored filtering is therefore defence in depth at the undertow transport boundary only. A route that carries an untrusted message from a non-undertow consumer into an undertow producer is not protected by this fix and must strip those headers itself.
CVE-2026-56139	Medium	2026-07-06	No exploit published	No public exploit	Generation of Error Message Containing Sensitive Information vulnerability in Apache Camel Undertow Component. The camel-undertow HTTP server consumer exposes a muteException option that controls what is returned to the client when a route processing error occurs. This option defaulted to false, whereas the other Camel HTTP server components (camel-http / camel-jetty / camel-servlet and camel-platform-http) default it to true. With muteException=false, when a request triggers an exception during route processing the consumer writes the full Throwable stack trace into the HTTP response body as text/plain instead of returning an empty body. Any unauthenticated client that can reach the endpoint and cause a processing error - for example by sending a malformed request body, an invalid parameter, or otherwise triggering a route-internal failure - therefore receives a complete Java stack trace. Such a stack trace can disclose sensitive internal information, including credentials embedded in exception messages, internal host names and IP addresses, filesystem paths, dependency and version details, database and class names, and the application's internal structure, which an attacker can use to plan further attacks. In addition, for Rest DSL consumers the muteException option was not honoured at all: the RestUndertowHttpBinding was created with a hard-coded false, so the stack trace was returned even when muteException=true had been configured. This issue affects Apache Camel: from 4.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0. Users are recommended to upgrade to version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. For deployments that cannot upgrade immediately, set muteException=true explicitly on the camel-undertow consumer (for example undertow: http://0.0.0.0:8080/api?muteException=true , or globally via the camel.component.undertow.mute-exception=true property), so that processing errors no longer return the stack trace to the client; note that on affected releases this workaround does not cover Rest DSL consumers, whose binding ignores the option until the fix is applied.
CVE-2026-28369	Critical	2026-03-27	No exploit published	No public exploit	A flaw was found in Undertow. When Undertow receives an HTTP request where the first header line starts with one or more spaces, it incorrectly processes the request by stripping these leading spaces. This behavior, which violates HTTP standards, can be exploited by a remote attacker to perform request smuggling. Request smuggling allows an attacker to bypass security mechanisms, access restricted information, or manipulate web caches, potentially leading to unauthorized actions or data exposure.
CVE-2026-28368	Critical	2026-03-27	No exploit published	No public exploit	A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.
CVE-2026-28367	Critical	2026-03-27	No exploit published	No public exploit	A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\r\r\r` as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.
CVE-2024-4027	High	2026-01-30	No exploit published	No public exploit	A flaw was found in Undertow. Servlets using a method that calls HttpServletRequestImpl.getParameterNames() can cause an OutOfMemoryError when the client sends a request with large parameter names. This issue can be exploited by an unauthorized user to cause a remote denial-of-service (DoS) attack.
CVE-2024-3884	High	2025-12-03	No exploit published	No public exploit	A flaw was found in Undertow that can cause remote denial of service attacks. When the server uses the FormEncodedDataDefinition.doParse(StreamSourceChannel) method to parse large form data encoding with application/x-www-form-urlencoded, the method will cause an OutOfMemory issue. This flaw allows unauthorized users to cause a remote denial of service (DoS) attack.
CVE-2025-9784	High	2025-09-02	No exploit published	No public exploit	A flaw was found in Undertow where malformed client requests can trigger server-side stream resets without triggering abuse counters. This issue, referred to as the "MadeYouReset" attack, allows malicious clients to induce excessive server workload by repeatedly causing server-side stream aborts. While not a protocol bug, this highlights a common implementation weakness that can be exploited to cause a denial of service (DoS).
CVE-2025-30177	Medium	2025-04-01	No exploit published	No public exploit	Bypass/Injection vulnerability in Apache Camel in Camel-Undertow component under particular conditions. This issue affects Apache Camel: from 4.10.0 before 4.10.3, from 4.8.0 before 4.8.6. Users are recommended to upgrade to version 4.10.3 for 4.10.x LTS and 4.8.6 for 4.8.x LTS. Camel undertow component is vulnerable to Camel message header injection, in particular the custom header filter strategy used by the component only filter the "out" direction, while it doesn't filter the "in" direction. This allows an attacker to include Camel specific headers that for some Camel components can alter the behaviour such as the camel-bean component, or the camel-exec component.
CVE-2023-4639	High	2024-11-17	No exploit published	No public exploit	A flaw was found in Undertow, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values, leading to unauthorized data access or modification. The main threat from this flaw impacts data confidentiality and integrity.
CVE-2023-1973	High	2024-11-07	No exploit published	No public exploit	A flaw was found in Undertow package. Using the FormAuthenticationMechanism, a malicious user could trigger a Denial of Service by sending crafted requests, leading the server to an OutofMemory error, exhausting the server's memory.
CVE-2024-7885	High	2024-08-21	No exploit published	No public exploit	A vulnerability was found in Undertow where the ProxyProtocolReadListener reuses the same StringBuilder instance across multiple requests. This issue occurs when the parseProxyProtocolV1 method processes multiple requests on the same HTTP connection. As a result, different requests may share the same StringBuilder instance, potentially leading to information leakage between requests or responses. In some cases, a value from a previous request or response may be erroneously reused, which could lead to unintended data exposure. This issue primarily results in errors and connection termination but creates a risk of data leakage in multi-request environments.
CVE-2024-5971	High	2024-07-08	No exploit published	No public exploit	A vulnerability was found in Undertow, where the chunked response hangs after the body was flushed. The response headers and body were sent but the client would continue waiting as Undertow does not send the expected 0\r\n termination of the chunked response. This results in uncontrolled resource consumption, leaving the server side to a denial of service attack. This happens only with Java 17 TLSv1.3 scenarios.
CVE-2024-3653	Medium	2024-07-08	No exploit published	No public exploit	A vulnerability was found in Undertow. This issue requires enabling the learning-push handler in the server's config, which is disabled by default, leaving the maxAge config in the handler unconfigured. The default is -1, which makes the handler vulnerable. If someone overwrites that config, the server is not subject to the attack. The attacker needs to be able to reach the server with a normal HTTP request.
CVE-2024-6162	High	2024-06-20	No exploit published	No public exploit	A vulnerability was found in Undertow, where URL-encoded request paths can be mishandled during concurrent requests on the AJP listener. This issue arises because the same buffer is used to decode the paths for multiple requests simultaneously, leading to incorrect path information being processed. As a result, the server may attempt to access the wrong path, causing errors such as "404 Not Found" or other application failures. This flaw can potentially lead to a denial of service, as legitimate resources become inaccessible due to the path mix-up.
CVE-2024-1635	High	2024-02-19	No exploit published	No public exploit	A vulnerability was found in Undertow. This vulnerability impacts a server that supports the wildfly-http-client protocol. Whenever a malicious user opens and closes a connection with the HTTP port of the server and then closes the connection immediately, the server will end with both memory and open file limits exhausted at some point, depending on the amount of memory available. At HTTP upgrade to remoting, the WriteTimeoutStreamSinkConduit leaks connections if RemotingConnection is closed by Remoting ServerConnectionOpenListener. Because the remoting connection originates in Undertow as part of the HTTP upgrade, there is an external layer to the remoting connection. This connection is unaware of the outermost layer when closing the connection during the connection opening procedure. Hence, the Undertow WriteTimeoutStreamSinkConduit is not notified of the closed connection in this scenario. Because WriteTimeoutStreamSinkConduit creates a timeout task, the whole dependency tree leaks via that task, which is added to XNIO WorkerThread. So, the workerThread points to the Undertow conduit, which contains the connections and causes the leak.
CVE-2024-1459	Medium	2024-02-12	Protected by Waratek	No public exploit	A path traversal vulnerability was found in Undertow. This issue may allow a remote attacker to append a specially-crafted sequence to an HTTP request for an application deployed to JBoss EAP, which may permit access to privileged or restricted files and directories.
CVE-2023-5379	High	2023-12-12	No exploit published	No public exploit	A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. This issue could allow a malicious user could to repeatedly send requests that exceed the max-header-size, causing a Denial of Service (DoS).
CVE-2023-3223	High	2023-09-27	No exploit published	No public exploit	A flaw was found in undertow. Servlets annotated with @MultipartConfig may cause an OutOfMemoryError due to large multipart content. This may allow unauthorized users to cause remote Denial of Service (DoS) attack. If the server uses fileSizeThreshold to limit the file size, it's possible to bypass the limit by setting the file name in the request to null.
CVE-2023-4853	High	2023-09-20	No exploit published	No public exploit	A flaw was found in Quarkus where HTTP security policies are not sanitizing certain character permutations correctly when accepting requests, resulting in incorrect evaluation of permissions. This issue could allow an attacker to bypass the security policy altogether, resulting in unauthorized endpoint access and possibly a denial of service.
CVE-2023-1108	High	2023-09-14	No exploit published	No public exploit	A flaw was found in undertow. This issue makes achieving a denial of service possible due to an unexpected handshake status updated in SslConduit, where the loop never terminates.
CVE-2022-4492	High	2023-02-23	No exploit published	No public exploit	The undertow client is not checking the server identity presented by the server certificate in https connections. This is a compulsory step (at least it should be performed by default) in https and in http/2. I would add it to any TLS client protocol.
CVE-2022-2764	Medium	2022-09-01	No exploit published	No public exploit	A flaw was found in Undertow. Denial of service can be achieved as Undertow server waits for the LAST_CHUNK forever for EJB invocations.
CVE-2022-1319	High	2022-08-31	No exploit published	No public exploit	A flaw was found in Undertow. For an AJP 400 response, EAP 7 is improperly sending two response packets, and those packets have the reuse flag set even though JBoss EAP closes the connection. A failure occurs when the connection is reused after a 400 by CPING since it reads in the second SEND_HEADERS response packet instead of a CPONG.
CVE-2022-1259	High	2022-08-31	No exploit published	No public exploit	A flaw was found in Undertow. A potential security issue in flow control handling by the browser over HTTP/2 may cause overhead or a denial of service in the server. This flaw exists because of an incomplete fix for CVE-2021-3629.
CVE-2021-3859	High	2022-08-26	No exploit published	No public exploit	A flaw was found in Undertow that tripped the client-side invocation timeout with certain calls made over HTTP2. This flaw allows an attacker to carry out denial of service attacks.
CVE-2021-3690	High	2022-08-23	No exploit published	No public exploit	A flaw was found in Undertow. A buffer leak on the incoming WebSocket PONG message may lead to memory exhaustion. This flaw allows an attacker to cause a denial of service. The highest threat from this vulnerability is availability.
CVE-2022-2053	High	2022-08-05	No exploit published	No public exploit	When a POST request comes through AJP and the request exceeds the max-post-size limit (maxEntitySize), Undertow's AjpServerRequestConduit implementation closes a connection without sending any response to the client/proxy. This behavior results in that a front-end proxy marking the backend worker (application server) as an error state and not forward requests to the worker for a while. In mod_cluster, this continues until the next STATUS request (10 seconds intervals) from the application server updates the server state. So, in the worst case, it can result in "All workers are in error state" and mod_cluster responds "503 Service Unavailable" for a while (up to 10 seconds). In mod_proxy_balancer, it does not forward requests to the worker until the "retry" timeout passes. However, luckily, mod_proxy_balancer has "forcerecovery" setting (On by default; this parameter can force the immediate recovery of all workers without considering the retry parameter of the workers if all workers of a balancer are in error state.). So, unlike mod_cluster, mod_proxy_balancer does not result in responding "503 Service Unavailable". An attacker could use this behavior to send a malicious request and trigger server errors, resulting in DoS (denial of service). This flaw was fixed in Undertow 2.2.19.Final, Undertow 2.3.0.Alpha2.
CVE-2021-3629	Medium	2022-05-24	No exploit published	No public exploit	A flaw was found in Undertow. A potential security issue in flow control handling by the browser over http/2 may potentially cause overhead or a denial of service in the server. The highest threat from this vulnerability is availability. This flaw affects Undertow versions prior to 2.0.40.Final and prior to 2.2.11.Final.
CVE-2021-3597	Medium	2022-05-24	No exploit published	No public exploit	A flaw was found in undertow. The HTTP2SourceChannel fails to write the final frame under some circumstances, resulting in a denial of service. The highest threat from this vulnerability is availability. This flaw affects Undertow versions prior to 2.0.35.SP1, prior to 2.2.6.SP1, prior to 2.2.7.SP1, prior to 2.0.36.SP1, prior to 2.2.9.Final and prior to 2.0.39.Final.
CVE-2019-19343	High	2021-03-23	No exploit published	No public exploit	A flaw was found in Undertow when using Remoting as shipped in Red Hat Jboss EAP before version 7.2.4. A memory leak in HttpOpenListener due to holding remote connections indefinitely may lead to denial of service. Versions before undertow 2.0.25.SP1 and jboss-remoting 5.0.14.SP1 are believed to be vulnerable.
CVE-2021-20220	Medium	2021-02-23	No exploit published	No public exploit	A flaw was found in Undertow. A regression in the fix for CVE-2020-10687 was found. HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own. The highest threat from this vulnerability is to data confidentiality and integrity.
CVE-2020-27782	High	2021-02-23	No exploit published	No public exploit	A flaw was found in the Undertow AJP connector. Malicious requests and abrupt connection closes could be triggered by an attacker using query strings with non-RFC compliant characters resulting in a denial of service. The highest threat from this vulnerability is to system availability. This affects Undertow 2.1.5.SP1, 2.0.33.SP2, and 2.2.3.SP1.
CVE-2020-10687	Medium	2020-09-23	No exploit published	No public exploit	A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.
CVE-2020-10705	High	2020-06-10	No exploit published	No public exploit	A flaw was discovered in Undertow in versions before Undertow 2.1.1.Final where certain requests to the "Expect: 100-continue" header may cause an out of memory error. This flaw may potentially lead to a denial of service.
CVE-2020-10719	Medium	2020-05-26	No exploit published	No public exploit	A flaw was found in Undertow in versions before 2.1.1.Final, regarding the processing of invalid HTTP requests with large chunk sizes. This flaw allows an attacker to take advantage of HTTP request smuggling.
CVE-2020-1757	High	2020-04-21	No exploit published	No public exploit	A flaw was found in all undertow-2.x.x SP1 versions prior to undertow-2.0.30.SP1, all undertow-1.x.x and undertow-2.x.x versions prior to undertow-2.1.0.Final, where the Servlet container causes servletPath to normalize incorrectly by truncating the path after semicolon which may lead to an application mapping resulting in the security bypass.
CVE-2019-14888	High	2020-01-23	No exploit published	No public exploit	A vulnerability was found in the Undertow HTTP server in versions before 2.0.28.SP1 when listening on HTTPS. An attacker can target the HTTPS port to carry out a Denial Of Service (DOS) to make the service unavailable on SSL.
CVE-2019-10184	High	2019-07-25	No exploit published	No public exploit	undertow before version 2.0.23.Final is vulnerable to an information leak issue. Web apps may have their directory structures predicted through requests without trailing slashes via the api.
CVE-2018-14642	Medium	2018-09-18	No exploit published	No public exploit	An information leak vulnerability was found in Undertow. If all headers are not written out in the first write() call then the code that handles flushing the buffer will always write out the full contents of the writevBuffer buffer, which may contain data from previous requests.
CVE-2018-1114	Medium	2018-09-11	No exploit published	No public exploit	It was found that URLResource.getLastModified() in Undertow closes the file descriptors only when they are finalized which can cause file descriptors to exhaust. This leads to a file handler leak.
CVE-2017-2670	High	2018-07-27	No exploit published	No public exploit	It was found in Undertow before 1.3.28 that with non-clean TCP close, the Websocket server gets into infinite loop on every IO thread, effectively causing DoS.
CVE-2017-2666	Medium	2018-07-27	No exploit published	No public exploit	It was discovered in Undertow that the code that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own.
CVE-2017-12165	High	2018-07-27	No exploit published	No public exploit	It was discovered that Undertow before 1.4.17, 1.3.31 and 2.0.0 processes http request headers with unusual whitespaces which can cause possible http request smuggling.
CVE-2018-1067	Medium	2018-05-21	No exploit published	No public exploit	In Undertow before versions 7.1.2.CR1, 7.1.2.GA it was found that the fix for CVE-2016-4993 was incomplete and Undertow web server is vulnerable to the injection of arbitrary HTTP headers, and also response splitting, due to insufficient sanitization and validation of user input before the input is used as part of an HTTP header value.
CVE-2017-12196	Medium	2018-04-18	No exploit published	No public exploit	undertow before versions 1.4.18.SP1, 2.0.2.Final, 1.4.24.Final was found vulnerable when using Digest authentication, the server does not ensure that the value of URI in the Authorization header matches the URI in HTTP request line. This allows the attacker to cause a MITM attack and access the desired content on the server.
CVE-2016-9589	High	2018-03-12	No exploit published	No public exploit	Undertow in Red Hat wildfly before version 11.0.0.Beta1 is vulnerable to a resource exhaustion resulting in a denial of service. Undertow keeps a cache of seen HTTP headers in persistent connections. It was found that this cache can easily exploited to fill memory with garbage, up to "max-headers" (default 200) * "max-header-size" (default 1MB) per active TCP connection.
CVE-2018-1048	High	2018-01-24	Protected by Waratek	No public exploit	It was found that the AJP connector in undertow, as shipped in Jboss EAP 7.1.0.GA, does not use the ALLOW_ENCODED_SLASH option and thus allow the the slash / anti-slash characters encoded in the url which may lead to path traversal and result in the information disclosure of arbitrary local files.
CVE-2018-1047	Medium	2018-01-24	Protected by Waratek	No public exploit	A flaw was found in Wildfly 9.x. A path traversal vulnerability through the org.wildfly.extension.undertow.deployment.ServletResourceManager.getResource method could lead to information disclosure of arbitrary local files.
CVE-2017-7559	Medium	2018-01-10	No exploit published	No public exploit	In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own.
CVE-2016-7046	Medium	2016-10-03	No exploit published	No public exploit	Red Hat JBoss Enterprise Application Platform (EAP) 7, when operating as a reverse-proxy with default buffer sizes, allows remote attackers to cause a denial of service (CPU and disk consumption) via a long URL.
CVE-2016-4993	Medium	2016-09-26	No exploit published	No public exploit	CRLF injection vulnerability in the Undertow web server in WildFly 10.0.0, as used in Red Hat JBoss Enterprise Application Platform (EAP) 7.x before 7.0.2, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via unspecified vectors.
CVE-2014-7816	Medium	2014-12-01	Protected by Waratek	No public exploit	Directory traversal vulnerability in JBoss Undertow 1.0.x before 1.0.17, 1.1.x before 1.1.0.CR5, and 1.2.x before 1.2.0.Beta3, when running on Windows, allows remote attackers to read arbitrary files via a .. (dot dot) in a resource URI.

CVE

Severity

Published▾

Status

Exploitation

Description

CVE-2026-78329

Critical

2026-08-24

No exploit published

No public exploit

Improper input validation vulnerability in Apache Camel Undertow component. This issue affects Apache Camel: from 4.11.0 before 4.14.9, from 4.15.0 before 4.18.4, from 4.19.0 before 4.22.0. UndertowEndpoint defaulted its headerFilterStrategy field to the base HttpHeaderFilterStrategy and pushed that instance into the UndertowHttpBinding it creates lazily, overwriting the UndertowHeaderFilterStrategy that DefaultUndertowHttpBinding installs in its own constructor. Unless a deployment supplied a custom binding or an explicit headerFilterStrategy, the undertow-specific filtering therefore never executed on endpoint-configured routes: the strategy object was constructed and immediately replaced before it could be consulted. The consequence is that the legacy websocket. Exchange-header prefix was not filtered at the undertow transport boundary in either direction, so an undertow HTTP consumer mapped inbound wire headers of that form onto the Exchange, where an undertow WebSocket producer reads them as dispatch directives and can be made to deliver to a peer other than the one the route selected; and header names that undertow itself does not accept were mapped onto the Exchange rather than being skipped. Rest DSL consumers were never affected, because UndertowComponent assigns UndertowRestHeaderFilterStrategy explicitly, which extends the undertow strategy. This is not a regression of CVE-2025-30177: the base HttpHeaderFilterStrategy configures the inbound Camel-prefix filter itself, so the protection introduced by that advisory continued to work through the base class and was never lost. What the change did was leave the undertow strategy orphaned on the endpoint path, with the effect that two subsequent corrections written into it - one skipping header names undertow rejects, one filtering the legacy websocket. prefix in both directions - were applied to a class the endpoint no longer used and never took effect in the releases that shipped them. Users are recommended to upgrade to version 4.22.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.9. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.4. For deployments that cannot upgrade immediately, configure the strategy explicitly rather than relying on the default, for example by binding an UndertowHeaderFilterStrategy in the registry and referencing it on the endpoint as undertow:http://0.0.0.0:8080/foo?headerFilterStrategy=#myStrategy, and additionally strip the dispatch headers at the trust boundary with removeHeaders(“websocket.*”). Note a residual limitation that upgrading does not remove: the undertow component deliberately keeps the websocket. values as part of its externally visible API contract, and UndertowProducer reads them with in.getHeader, which does not consult a HeaderFilterStrategy at all. The restored filtering is therefore defence in depth at the undertow transport boundary only. A route that carries an untrusted message from a non-undertow consumer into an undertow producer is not protected by this fix and must strip those headers itself.

CVE-2026-56139

Medium

2026-07-06

No exploit published

No public exploit

Generation of Error Message Containing Sensitive Information vulnerability in Apache Camel Undertow Component. The camel-undertow HTTP server consumer exposes a muteException option that controls what is returned to the client when a route processing error occurs. This option defaulted to false, whereas the other Camel HTTP server components (camel-http / camel-jetty / camel-servlet and camel-platform-http) default it to true. With muteException=false, when a request triggers an exception during route processing the consumer writes the full Throwable stack trace into the HTTP response body as text/plain instead of returning an empty body. Any unauthenticated client that can reach the endpoint and cause a processing error - for example by sending a malformed request body, an invalid parameter, or otherwise triggering a route-internal failure - therefore receives a complete Java stack trace. Such a stack trace can disclose sensitive internal information, including credentials embedded in exception messages, internal host names and IP addresses, filesystem paths, dependency and version details, database and class names, and the application's internal structure, which an attacker can use to plan further attacks. In addition, for Rest DSL consumers the muteException option was not honoured at all: the RestUndertowHttpBinding was created with a hard-coded false, so the stack trace was returned even when muteException=true had been configured. This issue affects Apache Camel: from 4.0.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0. Users are recommended to upgrade to version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. For deployments that cannot upgrade immediately, set muteException=true explicitly on the camel-undertow consumer (for example undertow: http://0.0.0.0:8080/api?muteException=true , or globally via the camel.component.undertow.mute-exception=true property), so that processing errors no longer return the stack trace to the client; note that on affected releases this workaround does not cover Rest DSL consumers, whose binding ignores the option until the fix is applied.

CVE-2026-28369

Critical

2026-03-27

No exploit published

No public exploit

A flaw was found in Undertow. When Undertow receives an HTTP request where the first header line starts with one or more spaces, it incorrectly processes the request by stripping these leading spaces. This behavior, which violates HTTP standards, can be exploited by a remote attacker to perform request smuggling. Request smuggling allows an attacker to bypass security mechanisms, access restricted information, or manipulate web caches, potentially leading to unauthorized actions or data exposure.

CVE-2026-28368

Critical

2026-03-27

No exploit published

No public exploit

A flaw was found in Undertow. This vulnerability allows a remote attacker to construct specially crafted requests where header names are parsed differently by Undertow compared to upstream proxies. This discrepancy in header interpretation can be exploited to launch request smuggling attacks, potentially bypassing security controls and accessing unauthorized resources.

CVE-2026-28367

Critical

2026-03-27

No exploit published

No public exploit

A flaw was found in Undertow. A remote attacker can exploit this vulnerability by sending `\r\r\r` as a header block terminator. This can be used for request smuggling with certain proxy servers, such as older versions of Apache Traffic Server and Google Cloud Classic Application Load Balancer, potentially leading to unauthorized access or manipulation of web requests.

CVE-2024-4027

High

2026-01-30

No exploit published

No public exploit

A flaw was found in Undertow. Servlets using a method that calls HttpServletRequestImpl.getParameterNames() can cause an OutOfMemoryError when the client sends a request with large parameter names. This issue can be exploited by an unauthorized user to cause a remote denial-of-service (DoS) attack.

CVE-2024-3884

High

2025-12-03

No exploit published

No public exploit

A flaw was found in Undertow that can cause remote denial of service attacks. When the server uses the FormEncodedDataDefinition.doParse(StreamSourceChannel) method to parse large form data encoding with application/x-www-form-urlencoded, the method will cause an OutOfMemory issue. This flaw allows unauthorized users to cause a remote denial of service (DoS) attack.

CVE-2025-9784

High

2025-09-02

No exploit published

No public exploit

A flaw was found in Undertow where malformed client requests can trigger server-side stream resets without triggering abuse counters. This issue, referred to as the "MadeYouReset" attack, allows malicious clients to induce excessive server workload by repeatedly causing server-side stream aborts. While not a protocol bug, this highlights a common implementation weakness that can be exploited to cause a denial of service (DoS).

CVE-2025-30177

Medium

2025-04-01

No exploit published

No public exploit

Bypass/Injection vulnerability in Apache Camel in Camel-Undertow component under particular conditions. This issue affects Apache Camel: from 4.10.0 before 4.10.3, from 4.8.0 before 4.8.6. Users are recommended to upgrade to version 4.10.3 for 4.10.x LTS and 4.8.6 for 4.8.x LTS. Camel undertow component is vulnerable to Camel message header injection, in particular the custom header filter strategy used by the component only filter the "out" direction, while it doesn't filter the "in" direction. This allows an attacker to include Camel specific headers that for some Camel components can alter the behaviour such as the camel-bean component, or the camel-exec component.

CVE-2023-4639

High

2024-11-17

No exploit published

No public exploit

A flaw was found in Undertow, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values, leading to unauthorized data access or modification. The main threat from this flaw impacts data confidentiality and integrity.

CVE-2023-1973

High

2024-11-07

No exploit published

No public exploit

A flaw was found in Undertow package. Using the FormAuthenticationMechanism, a malicious user could trigger a Denial of Service by sending crafted requests, leading the server to an OutofMemory error, exhausting the server's memory.

CVE-2024-7885

High

2024-08-21

No exploit published

No public exploit

A vulnerability was found in Undertow where the ProxyProtocolReadListener reuses the same StringBuilder instance across multiple requests. This issue occurs when the parseProxyProtocolV1 method processes multiple requests on the same HTTP connection. As a result, different requests may share the same StringBuilder instance, potentially leading to information leakage between requests or responses. In some cases, a value from a previous request or response may be erroneously reused, which could lead to unintended data exposure. This issue primarily results in errors and connection termination but creates a risk of data leakage in multi-request environments.

CVE-2024-5971

High

2024-07-08

No exploit published

No public exploit

A vulnerability was found in Undertow, where the chunked response hangs after the body was flushed. The response headers and body were sent but the client would continue waiting as Undertow does not send the expected 0\r\n termination of the chunked response. This results in uncontrolled resource consumption, leaving the server side to a denial of service attack. This happens only with Java 17 TLSv1.3 scenarios.

CVE-2024-3653

Medium

2024-07-08

No exploit published

No public exploit

A vulnerability was found in Undertow. This issue requires enabling the learning-push handler in the server's config, which is disabled by default, leaving the maxAge config in the handler unconfigured. The default is -1, which makes the handler vulnerable. If someone overwrites that config, the server is not subject to the attack. The attacker needs to be able to reach the server with a normal HTTP request.

CVE-2024-6162

High

2024-06-20

No exploit published

No public exploit

A vulnerability was found in Undertow, where URL-encoded request paths can be mishandled during concurrent requests on the AJP listener. This issue arises because the same buffer is used to decode the paths for multiple requests simultaneously, leading to incorrect path information being processed. As a result, the server may attempt to access the wrong path, causing errors such as "404 Not Found" or other application failures. This flaw can potentially lead to a denial of service, as legitimate resources become inaccessible due to the path mix-up.

CVE-2024-1635

High

2024-02-19

No exploit published

No public exploit

A vulnerability was found in Undertow. This vulnerability impacts a server that supports the wildfly-http-client protocol. Whenever a malicious user opens and closes a connection with the HTTP port of the server and then closes the connection immediately, the server will end with both memory and open file limits exhausted at some point, depending on the amount of memory available. At HTTP upgrade to remoting, the WriteTimeoutStreamSinkConduit leaks connections if RemotingConnection is closed by Remoting ServerConnectionOpenListener. Because the remoting connection originates in Undertow as part of the HTTP upgrade, there is an external layer to the remoting connection. This connection is unaware of the outermost layer when closing the connection during the connection opening procedure. Hence, the Undertow WriteTimeoutStreamSinkConduit is not notified of the closed connection in this scenario. Because WriteTimeoutStreamSinkConduit creates a timeout task, the whole dependency tree leaks via that task, which is added to XNIO WorkerThread. So, the workerThread points to the Undertow conduit, which contains the connections and causes the leak.

CVE-2024-1459

Medium

2024-02-12

Protected by Waratek

No public exploit

A path traversal vulnerability was found in Undertow. This issue may allow a remote attacker to append a specially-crafted sequence to an HTTP request for an application deployed to JBoss EAP, which may permit access to privileged or restricted files and directories.

CVE-2023-5379

High

2023-12-12

No exploit published

No public exploit

A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. This issue could allow a malicious user could to repeatedly send requests that exceed the max-header-size, causing a Denial of Service (DoS).

CVE-2023-3223

High

2023-09-27

No exploit published

No public exploit

A flaw was found in undertow. Servlets annotated with @MultipartConfig may cause an OutOfMemoryError due to large multipart content. This may allow unauthorized users to cause remote Denial of Service (DoS) attack. If the server uses fileSizeThreshold to limit the file size, it's possible to bypass the limit by setting the file name in the request to null.

CVE-2023-4853

High

2023-09-20

No exploit published

No public exploit

A flaw was found in Quarkus where HTTP security policies are not sanitizing certain character permutations correctly when accepting requests, resulting in incorrect evaluation of permissions. This issue could allow an attacker to bypass the security policy altogether, resulting in unauthorized endpoint access and possibly a denial of service.

CVE-2023-1108

High

2023-09-14

No exploit published

No public exploit

A flaw was found in undertow. This issue makes achieving a denial of service possible due to an unexpected handshake status updated in SslConduit, where the loop never terminates.

CVE-2022-4492

High

2023-02-23

No exploit published

No public exploit

The undertow client is not checking the server identity presented by the server certificate in https connections. This is a compulsory step (at least it should be performed by default) in https and in http/2. I would add it to any TLS client protocol.

CVE-2022-2764

Medium

2022-09-01

No exploit published

No public exploit

A flaw was found in Undertow. Denial of service can be achieved as Undertow server waits for the LAST_CHUNK forever for EJB invocations.

CVE-2022-1319

High

2022-08-31

No exploit published

No public exploit

A flaw was found in Undertow. For an AJP 400 response, EAP 7 is improperly sending two response packets, and those packets have the reuse flag set even though JBoss EAP closes the connection. A failure occurs when the connection is reused after a 400 by CPING since it reads in the second SEND_HEADERS response packet instead of a CPONG.

CVE-2022-1259

High

2022-08-31

No exploit published

No public exploit

A flaw was found in Undertow. A potential security issue in flow control handling by the browser over HTTP/2 may cause overhead or a denial of service in the server. This flaw exists because of an incomplete fix for CVE-2021-3629.

CVE-2021-3859

High

2022-08-26

No exploit published

No public exploit

A flaw was found in Undertow that tripped the client-side invocation timeout with certain calls made over HTTP2. This flaw allows an attacker to carry out denial of service attacks.

CVE-2021-3690

High

2022-08-23

No exploit published

No public exploit

A flaw was found in Undertow. A buffer leak on the incoming WebSocket PONG message may lead to memory exhaustion. This flaw allows an attacker to cause a denial of service. The highest threat from this vulnerability is availability.

CVE-2022-2053

High

2022-08-05

No exploit published

No public exploit

When a POST request comes through AJP and the request exceeds the max-post-size limit (maxEntitySize), Undertow's AjpServerRequestConduit implementation closes a connection without sending any response to the client/proxy. This behavior results in that a front-end proxy marking the backend worker (application server) as an error state and not forward requests to the worker for a while. In mod_cluster, this continues until the next STATUS request (10 seconds intervals) from the application server updates the server state. So, in the worst case, it can result in "All workers are in error state" and mod_cluster responds "503 Service Unavailable" for a while (up to 10 seconds). In mod_proxy_balancer, it does not forward requests to the worker until the "retry" timeout passes. However, luckily, mod_proxy_balancer has "forcerecovery" setting (On by default; this parameter can force the immediate recovery of all workers without considering the retry parameter of the workers if all workers of a balancer are in error state.). So, unlike mod_cluster, mod_proxy_balancer does not result in responding "503 Service Unavailable". An attacker could use this behavior to send a malicious request and trigger server errors, resulting in DoS (denial of service). This flaw was fixed in Undertow 2.2.19.Final, Undertow 2.3.0.Alpha2.

CVE-2021-3629

Medium

2022-05-24

No exploit published

No public exploit

A flaw was found in Undertow. A potential security issue in flow control handling by the browser over http/2 may potentially cause overhead or a denial of service in the server. The highest threat from this vulnerability is availability. This flaw affects Undertow versions prior to 2.0.40.Final and prior to 2.2.11.Final.

CVE-2021-3597

Medium

2022-05-24

No exploit published

No public exploit

A flaw was found in undertow. The HTTP2SourceChannel fails to write the final frame under some circumstances, resulting in a denial of service. The highest threat from this vulnerability is availability. This flaw affects Undertow versions prior to 2.0.35.SP1, prior to 2.2.6.SP1, prior to 2.2.7.SP1, prior to 2.0.36.SP1, prior to 2.2.9.Final and prior to 2.0.39.Final.

CVE-2019-19343

High

2021-03-23

No exploit published

No public exploit

A flaw was found in Undertow when using Remoting as shipped in Red Hat Jboss EAP before version 7.2.4. A memory leak in HttpOpenListener due to holding remote connections indefinitely may lead to denial of service. Versions before undertow 2.0.25.SP1 and jboss-remoting 5.0.14.SP1 are believed to be vulnerable.

CVE-2021-20220

Medium

2021-02-23

No exploit published

No public exploit

A flaw was found in Undertow. A regression in the fix for CVE-2020-10687 was found. HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own. The highest threat from this vulnerability is to data confidentiality and integrity.

CVE-2020-27782

High

2021-02-23

No exploit published

No public exploit

A flaw was found in the Undertow AJP connector. Malicious requests and abrupt connection closes could be triggered by an attacker using query strings with non-RFC compliant characters resulting in a denial of service. The highest threat from this vulnerability is to system availability. This affects Undertow 2.1.5.SP1, 2.0.33.SP2, and 2.2.3.SP1.

CVE-2020-10687

Medium

2020-09-23

No exploit published

No public exploit

A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.

CVE-2020-10705

High

2020-06-10

No exploit published

No public exploit

A flaw was discovered in Undertow in versions before Undertow 2.1.1.Final where certain requests to the "Expect: 100-continue" header may cause an out of memory error. This flaw may potentially lead to a denial of service.

CVE-2020-10719

Medium

2020-05-26

No exploit published

No public exploit

A flaw was found in Undertow in versions before 2.1.1.Final, regarding the processing of invalid HTTP requests with large chunk sizes. This flaw allows an attacker to take advantage of HTTP request smuggling.

CVE-2020-1757

High

2020-04-21

No exploit published

No public exploit

A flaw was found in all undertow-2.x.x SP1 versions prior to undertow-2.0.30.SP1, all undertow-1.x.x and undertow-2.x.x versions prior to undertow-2.1.0.Final, where the Servlet container causes servletPath to normalize incorrectly by truncating the path after semicolon which may lead to an application mapping resulting in the security bypass.

CVE-2019-14888

High

2020-01-23

No exploit published

No public exploit

A vulnerability was found in the Undertow HTTP server in versions before 2.0.28.SP1 when listening on HTTPS. An attacker can target the HTTPS port to carry out a Denial Of Service (DOS) to make the service unavailable on SSL.

CVE-2019-10184

High

2019-07-25

No exploit published

No public exploit

undertow before version 2.0.23.Final is vulnerable to an information leak issue. Web apps may have their directory structures predicted through requests without trailing slashes via the api.

CVE-2018-14642

Medium

2018-09-18

No exploit published

No public exploit

An information leak vulnerability was found in Undertow. If all headers are not written out in the first write() call then the code that handles flushing the buffer will always write out the full contents of the writevBuffer buffer, which may contain data from previous requests.

CVE-2018-1114

Medium

2018-09-11

No exploit published

No public exploit

It was found that URLResource.getLastModified() in Undertow closes the file descriptors only when they are finalized which can cause file descriptors to exhaust. This leads to a file handler leak.

CVE-2017-2670

High

2018-07-27

No exploit published

No public exploit

It was found in Undertow before 1.3.28 that with non-clean TCP close, the Websocket server gets into infinite loop on every IO thread, effectively causing DoS.

CVE-2017-2666

Medium

2018-07-27

No exploit published

No public exploit

It was discovered in Undertow that the code that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own.

CVE-2017-12165

High

2018-07-27

No exploit published

No public exploit

It was discovered that Undertow before 1.4.17, 1.3.31 and 2.0.0 processes http request headers with unusual whitespaces which can cause possible http request smuggling.

CVE-2018-1067

Medium

2018-05-21

No exploit published

No public exploit

In Undertow before versions 7.1.2.CR1, 7.1.2.GA it was found that the fix for CVE-2016-4993 was incomplete and Undertow web server is vulnerable to the injection of arbitrary HTTP headers, and also response splitting, due to insufficient sanitization and validation of user input before the input is used as part of an HTTP header value.

CVE-2017-12196

Medium

2018-04-18

No exploit published

No public exploit

undertow before versions 1.4.18.SP1, 2.0.2.Final, 1.4.24.Final was found vulnerable when using Digest authentication, the server does not ensure that the value of URI in the Authorization header matches the URI in HTTP request line. This allows the attacker to cause a MITM attack and access the desired content on the server.

CVE-2016-9589

High

2018-03-12

No exploit published

No public exploit

Undertow in Red Hat wildfly before version 11.0.0.Beta1 is vulnerable to a resource exhaustion resulting in a denial of service. Undertow keeps a cache of seen HTTP headers in persistent connections. It was found that this cache can easily exploited to fill memory with garbage, up to "max-headers" (default 200) * "max-header-size" (default 1MB) per active TCP connection.

CVE-2018-1048

High

2018-01-24

Protected by Waratek

No public exploit

It was found that the AJP connector in undertow, as shipped in Jboss EAP 7.1.0.GA, does not use the ALLOW_ENCODED_SLASH option and thus allow the the slash / anti-slash characters encoded in the url which may lead to path traversal and result in the information disclosure of arbitrary local files.

CVE-2018-1047

Medium

2018-01-24

Protected by Waratek

No public exploit

A flaw was found in Wildfly 9.x. A path traversal vulnerability through the org.wildfly.extension.undertow.deployment.ServletResourceManager.getResource method could lead to information disclosure of arbitrary local files.

CVE-2017-7559

Medium

2018-01-10

No exploit published

No public exploit

In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response. By manipulating the HTTP response the attacker could poison a web-cache, perform an XSS attack, or obtain sensitive information from requests other than their own.

CVE-2016-7046

Medium

2016-10-03

No exploit published

No public exploit

Red Hat JBoss Enterprise Application Platform (EAP) 7, when operating as a reverse-proxy with default buffer sizes, allows remote attackers to cause a denial of service (CPU and disk consumption) via a long URL.

CVE-2016-4993

Medium

2016-09-26

No exploit published

No public exploit

CRLF injection vulnerability in the Undertow web server in WildFly 10.0.0, as used in Red Hat JBoss Enterprise Application Platform (EAP) 7.x before 7.0.2, allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via unspecified vectors.

CVE-2014-7816

Medium

2014-12-01

Protected by Waratek

No public exploit

Directory traversal vulnerability in JBoss Undertow 1.0.x before 1.0.17, 1.1.x before 1.1.0.CR5, and 1.2.x before 1.2.0.Beta3, when running on Windows, allows remote attackers to read arbitrary files via a .. (dot dot) in a resource URI.