Critical CWE-636 CVEs

CVE	Severity	Published▾	Status	Exploitation	Description
CVE-2026-110985	Critical	2026-10-28	No exploit published	No public exploit	A Kafka broker using SASL/OAUTHBEARER with the default validator (sasl.oauthbearer.jwt.validator.class=DefaultJwtValidator) selects its implementation from configuration. When sasl.oauthbearer.jwks.endpoint.url is set, the validator verifies the JWT signature. When that URL is unset (the default) and no verification key resolver is supplied, DefaultJwtValidator silently falls back to ClientJwtValidator, which does not verify the JWT signature, algorithm, or issuer - and the broker starts with no warning or error. This is the residual of CVE-2026-33557, whose fix restored signature verification only on the path where the JWKS endpoint URL is set. Impact: A broker in this state accepts any structurally valid JWT, including "alg":"none" tokens. An unauthenticated remote attacker who can reach the listener can forge a token asserting any principal - including configured superusers - and gain full access to the cluster. Only brokers that enable SASL/OAUTHBEARER validation without a JWKS endpoint URL (and without a custom verification key resolver) are affected; brokers that set the URL verify signatures and are not affected. Unlike CVE-2026-110952 (issuer/audience not enforced by default), here no signature is verified at all. Mitigation (all affected versions, no upgrade required): Set sasl.oauthbearer.jwks.endpoint.url for every listener/mechanism that uses OAuthBearerValidatorCallbackHandler, or configure a signature-verifying sasl.oauthbearer.jwt.validator.class. Resolution: From Apache Kafka 4.2.2, 4.3.1, and 4.4.0: a broker that would fall back to the non-verifying ClientJwtValidator fails to start with a ConfigException instead of running without signature verification (secure by default).
CVE-2026-95848	Critical	2026-09-23	No exploit published	Proof of concept only	Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, when a configured authenticator or authorizator class cannot be loaded, Server.initializeAuthenticator and Server.initializeAuthorizatorPolicy treat the failure as though no custom class was configured and fall back to AcceptAllAuthenticator or PermitAllAuthorizatorPolicy. A misspelled class name, missing dependency, constructor failure, or classpath problem can therefore start the broker with authentication or authorization disabled even though the operator configured those controls. This issue is fixed in version 0.18.1.
CVE-2026-53913	Critical	2026-07-06	No exploit published	No public exploit	Improper Authentication, Missing Authentication for Critical Function, Not Failing Securely ('Failing Open') vulnerability in Apache Camel Keycloak Component. The KeycloakSecurityPolicy of camel-keycloak guards a route by running KeycloakSecurityProcessor.beforeProcess(), which performs three checks in sequence: it rejects a request that carries no access token, then - only if requiredRoles is non-empty - validates the roles, and - only if requiredPermissions is non-empty - validates the permissions. The actual cryptographic verification of the bearer access token (signature, issuer and expiry for a local JWT, or active-state and issuer for token introspection) is performed exclusively inside those role and permission checks. KeycloakSecurityPolicy defaults requiredRoles and requiredPermissions to empty - which is the documented 'Basic Setup' - so on a route configured that way the role and permission checks are skipped and the access token is therefore never verified. The token-presence check still rejects a missing token, but an invalid token is accepted: any non-null value in the Authorization: Bearer header - including an arbitrary string or a forged, unsigned JWT - passes the policy and the request reaches the protected route, with no signature, issuer or expiry check and no request to Keycloak. The token is read from the inbound request header because allowTokenFromHeader defaults to true. Because the normal reason to place a route behind this policy is that the route performs server-side work, the bypass results in unauthenticated access to that work; where the protected route forwards to a code-execution-capable producer, it can result in unauthenticated remote code execution. This defect is independent of CVE-2026-23552: that issue concerned the issuer claim and was fixed by adding a check inside the verification routine, but here the verification routine is not reached at all in the default configuration, so the defect remains. This issue affects Apache Camel: 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 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. For deployments that cannot upgrade immediately, configure a non-empty requiredRoles or requiredPermissions on every KeycloakSecurityPolicy so that the token-verification path is exercised, set allowTokenFromHeader to false where the token is not expected from the request header, or perform token verification at the framework layer ahead of the policy.

CVE

Severity

Published▾

Status

Exploitation

Description

CVE-2026-110985

Critical

2026-10-28

No exploit published

No public exploit

A Kafka broker using SASL/OAUTHBEARER with the default validator (sasl.oauthbearer.jwt.validator.class=DefaultJwtValidator) selects its implementation from configuration. When sasl.oauthbearer.jwks.endpoint.url is set, the validator verifies the JWT signature. When that URL is unset (the default) and no verification key resolver is supplied, DefaultJwtValidator silently falls back to ClientJwtValidator, which does not verify the JWT signature, algorithm, or issuer - and the broker starts with no warning or error. This is the residual of CVE-2026-33557, whose fix restored signature verification only on the path where the JWKS endpoint URL is set. Impact: A broker in this state accepts any structurally valid JWT, including "alg":"none" tokens. An unauthenticated remote attacker who can reach the listener can forge a token asserting any principal - including configured superusers - and gain full access to the cluster. Only brokers that enable SASL/OAUTHBEARER validation without a JWKS endpoint URL (and without a custom verification key resolver) are affected; brokers that set the URL verify signatures and are not affected. Unlike CVE-2026-110952 (issuer/audience not enforced by default), here no signature is verified at all. Mitigation (all affected versions, no upgrade required): Set sasl.oauthbearer.jwks.endpoint.url for every listener/mechanism that uses OAuthBearerValidatorCallbackHandler, or configure a signature-verifying sasl.oauthbearer.jwt.validator.class. Resolution: From Apache Kafka 4.2.2, 4.3.1, and 4.4.0: a broker that would fall back to the non-verifying ClientJwtValidator fails to start with a ConfigException instead of running without signature verification (secure by default).

CVE-2026-95848

Critical

2026-09-23

No exploit published

Proof of concept only

Moquette is a lightweight Java MQTT broker. Prior to 0.18.1, when a configured authenticator or authorizator class cannot be loaded, Server.initializeAuthenticator and Server.initializeAuthorizatorPolicy treat the failure as though no custom class was configured and fall back to AcceptAllAuthenticator or PermitAllAuthorizatorPolicy. A misspelled class name, missing dependency, constructor failure, or classpath problem can therefore start the broker with authentication or authorization disabled even though the operator configured those controls. This issue is fixed in version 0.18.1.

CVE-2026-53913

Critical

2026-07-06

No exploit published

No public exploit

Improper Authentication, Missing Authentication for Critical Function, Not Failing Securely ('Failing Open') vulnerability in Apache Camel Keycloak Component. The KeycloakSecurityPolicy of camel-keycloak guards a route by running KeycloakSecurityProcessor.beforeProcess(), which performs three checks in sequence: it rejects a request that carries no access token, then - only if requiredRoles is non-empty - validates the roles, and - only if requiredPermissions is non-empty - validates the permissions. The actual cryptographic verification of the bearer access token (signature, issuer and expiry for a local JWT, or active-state and issuer for token introspection) is performed exclusively inside those role and permission checks. KeycloakSecurityPolicy defaults requiredRoles and requiredPermissions to empty - which is the documented 'Basic Setup' - so on a route configured that way the role and permission checks are skipped and the access token is therefore never verified. The token-presence check still rejects a missing token, but an invalid token is accepted: any non-null value in the Authorization: Bearer header - including an arbitrary string or a forged, unsigned JWT - passes the policy and the request reaches the protected route, with no signature, issuer or expiry check and no request to Keycloak. The token is read from the inbound request header because allowTokenFromHeader defaults to true. Because the normal reason to place a route behind this policy is that the route performs server-side work, the bypass results in unauthenticated access to that work; where the protected route forwards to a code-execution-capable producer, it can result in unauthenticated remote code execution. This defect is independent of CVE-2026-23552: that issue concerned the issuer claim and was fixed by adding a check inside the verification routine, but here the verification routine is not reached at all in the default configuration, so the defect remains. This issue affects Apache Camel: 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 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. For deployments that cannot upgrade immediately, configure a non-empty requiredRoles or requiredPermissions on every KeycloakSecurityPolicy so that the token-verification path is exercised, set allowTokenFromHeader to false where the token is not expected from the request header, or perform token verification at the framework layer ahead of the policy.