`CVE-2026-55955` Apache Tomcat

Affected software	Apache Tomcat
Severity	6.5 Medium CVSS 3.1
Fixed in	`11.0.23`, `10.1.56`, `9.0.119`
Weakness	Improper authentication (CWE-287)
Published	29 Jun 2026
Updated	25 Oct 2026

Description

Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.13 through 9.0.18, from 8.5.38 through 8.5.100, from 7.0.100 through 7.0.109. Users are recommended to upgrade to version 11.0.23, 10.1.56, 9.0.119, which fixes the issue.

Exploitation status

No public exploit

No exploit has been reported in the sources we check.

CISA KEV not listed
VulnCheck KEV not listed
CISA Vulnrichment exploitation: none
Indexed PoC none indexed
EPSS 0.44% chance in 30 days

Waratek protection

No exploit published

Within Waratek scope. In the sources we check, nobody has published exploit code for this CVE or reported it being exploited.

A public code fix exists: apache/tomcat 3a9ff01.

Protection none
Action unverified
Review automated Upstream data
Record active

Decided by	Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all
Finding	This CVE is not listed in CISA KEV or VulnCheck KEV, CISA Vulnrichment records no active exploitation, no reviewed exploit catalogue carries an entry for it, and no GitHub PoC repository for it has 5 or more stars. Nobody has published exploit code worth tracing, so it is not a candidate for a rule ahead of the ones where somebody has; an upstream fix path does exist, so the remediation half of the candidacy still holds. This is a statement about what has been published, not about whether the defect is reachable or serious.

Decided by

Exploit code for this candidate, published in a reviewed catalogue or a GitHub repository with 5 or more stars, or in use per CISA or VulnCheck; not only a CISA verdict, a forecast, or nothing at all

Finding

This CVE is not listed in CISA KEV or VulnCheck KEV, CISA Vulnrichment records no active exploitation, no reviewed exploit catalogue carries an entry for it, and no GitHub PoC repository for it has 5 or more stars. Nobody has published exploit code worth tracing, so it is not a candidate for a rule ahead of the ones where somebody has; an upstream fix path does exist, so the remediation half of the candidacy still holds. This is a statement about what has been published, not about whether the defect is reachable or serious.

Affected software and releases

Oracle advisories

Advisory	Type	Quarter	Products Oracle names in its risk matrix
Oracle Critical Patch Update October 2026 ↗	CPU	2026-Q4	Oracle Communications / Alarms, KPI, and Measurements (Apache Tomcat) (25.2.200) Oracle Communications / CMP (Apache Tomcat) (15.0.0.0.0, 15.1.0.0.0) Oracle Communications / Microservices (Apache Tomcat) (7.0.0) Oracle Communications / Platform (Apache Tomcat) (47.0.0.2.0) Oracle Hospitality Applications / Next-Gen SPMS (Apache Tomcat) (23.1, 23.2, 23.3) Oracle Retail Applications / Xenvironment (Apache Tomcat) (21.0.5, 22.0.3, 23.0.3, 24.0.2, 25.0.1, 26.0.0)
Oracle Critical Security Patch Update August 2026 ↗	CSPU	2026-Q3	Oracle Communications / Security (Apache Tomcat) (25.2.0.0.10)
Oracle Critical Security Patch Update September 2026 ↗	CSPU	2026-Q3	Oracle Siebel CRM / EAI (Apache Tomcat) (17.0-26.7)

Advisory

Type

Quarter

Products Oracle names in its risk matrix

Oracle Critical Patch Update October 2026 ↗

CPU

2026-Q4

Oracle Communications / Alarms, KPI, and Measurements (Apache Tomcat) (25.2.200)
Oracle Communications / CMP (Apache Tomcat) (15.0.0.0.0, 15.1.0.0.0)
Oracle Communications / Microservices (Apache Tomcat) (7.0.0)
Oracle Communications / Platform (Apache Tomcat) (47.0.0.2.0)
Oracle Hospitality Applications / Next-Gen SPMS (Apache Tomcat) (23.1, 23.2, 23.3)
Oracle Retail Applications / Xenvironment (Apache Tomcat) (21.0.5, 22.0.3, 23.0.3, 24.0.2, 25.0.1, 26.0.0)

Oracle Critical Security Patch Update August 2026 ↗

CSPU

2026-Q3

Oracle Communications / Security (Apache Tomcat) (25.2.0.0.10)

Oracle Critical Security Patch Update September 2026 ↗

CSPU

2026-Q3

Oracle Siebel CRM / EAI (Apache Tomcat) (17.0-26.7)

Oracle components and versions

Family	Component	Versions, as Oracle lists them	Read as
Oracle Communications	Alarms, KPI, and Measurements (Apache Tomcat)	25.2.200	25.2.200
Oracle Communications	CMP (Apache Tomcat)	15.0.0.0.0, 15.1.0.0.0	15.0.0.0.0 · 15.1.0.0.0
Oracle Communications	Microservices (Apache Tomcat)	7.0.0	7.0.0
Oracle Communications	Platform (Apache Tomcat)	47.0.0.2.0	47.0.0.2.0
Oracle Communications	Security (Apache Tomcat)	25.2.0.0.10	25.2.0.0.10
Oracle Hospitality Applications	Next-Gen SPMS (Apache Tomcat)	23.1, 23.2, 23.3	23.1 · 23.2 · 23.3
Oracle Retail Applications	Xenvironment (Apache Tomcat)	21.0.5, 22.0.3, 23.0.3, 24.0.2, 25.0.1, 26.0.0	21.0.5 · 22.0.3 · 23.0.3 · 24.0.2 · 25.0.1 · 26.0.0
Oracle Siebel CRM	EAI (Apache Tomcat)	17.0-26.7

Family

Component

Versions, as Oracle lists them

Read as

Oracle Communications

Alarms, KPI, and Measurements (Apache Tomcat)

25.2.200

Oracle Communications

CMP (Apache Tomcat)

15.0.0.0.0, 15.1.0.0.0

15.0.0.0.0 · 15.1.0.0.0

Oracle Communications

Microservices (Apache Tomcat)

7.0.0

Oracle Communications

Platform (Apache Tomcat)

47.0.0.2.0

Oracle Communications

Security (Apache Tomcat)

25.2.0.0.10

Oracle Hospitality Applications

Next-Gen SPMS (Apache Tomcat)

23.1, 23.2, 23.3

23.1 · 23.2 · 23.3

Oracle Retail Applications

Xenvironment (Apache Tomcat)

21.0.5, 22.0.3, 23.0.3, 24.0.2, 25.0.1, 26.0.0

21.0.5 · 22.0.3 · 23.0.3 · 24.0.2 · 25.0.1 · 26.0.0

Oracle Siebel CRM

EAI (Apache Tomcat)

17.0-26.7

Maven packages

Affected and fixed versions, from OSV.dev

Package Introduced Fixed Last affected

org.apache.tomcat:tomcat 11.0.0-M1 11.0.23 unbounded

org.apache.tomcat:tomcat 10.1.0-M1 10.1.56 unbounded

org.apache.tomcat:tomcat 9.0.13 9.0.119 unbounded

org.apache.tomcat:tomcat 8.5.38 none 8.5.100

org.apache.tomcat:tomcat 7.0.100 none 7.0.109

org.apache.tomcat:tomcat-tribes 11.0.0-M1 11.0.23 unbounded

org.apache.tomcat:tomcat-tribes 10.1.0-M1 10.1.56 unbounded

org.apache.tomcat:tomcat-tribes 9.0.13 9.0.119 unbounded

org.apache.tomcat:tomcat-tribes 8.5.38 none 8.5.100

org.apache.tomcat:tomcat-tribes 7.0.100 none 7.0.109

Package	Introduced	Fixed	Last affected
`org.apache.tomcat:tomcat`	11.0.0-M1	`11.0.23`	unbounded
`org.apache.tomcat:tomcat`	10.1.0-M1	`10.1.56`	unbounded
`org.apache.tomcat:tomcat`	9.0.13	`9.0.119`	unbounded
`org.apache.tomcat:tomcat`	8.5.38	none	8.5.100
`org.apache.tomcat:tomcat`	7.0.100	none	7.0.109
`org.apache.tomcat:tomcat-tribes`	11.0.0-M1	`11.0.23`	unbounded
`org.apache.tomcat:tomcat-tribes`	10.1.0-M1	`10.1.56`	unbounded
`org.apache.tomcat:tomcat-tribes`	9.0.13	`9.0.119`	unbounded
`org.apache.tomcat:tomcat-tribes`	8.5.38	none	8.5.100
`org.apache.tomcat:tomcat-tribes`	7.0.100	none	7.0.109

Products and versions

3 products, 13 version entries

Source	Vendor	Product	Scheme	Affected versions
nvd	apache	tomcat	generic	＜ 9.0.119 · ≥ 10.1.0 and ＜ 10.1.56 · ≥ 11.0.0 and ＜ 11.0.23
osv	org.apache.tomcat	tomcat	generic	≥ 7.0.100 and ≤ 7.0.109 · ≥ 8.5.38 and ≤ 8.5.100 · ≥ 9.0.13 and ＜ 9.0.119 · ≥ 10.1.0 and ＜ 10.1.56 · ≥ 11.0.0 and ＜ 11.0.23
osv	org.apache.tomcat	tomcat-tribes	generic	≥ 7.0.100 and ≤ 7.0.109 · ≥ 8.5.38 and ≤ 8.5.100 · ≥ 9.0.13 and ＜ 9.0.119 · ≥ 10.1.0 and ＜ 10.1.56 · ≥ 11.0.0 and ＜ 11.0.23

Source

Vendor

Product

Scheme

Affected versions

nvd

apache

tomcat

generic

＜ 9.0.119 · ≥ 10.1.0 and ＜ 10.1.56 · ≥ 11.0.0 and ＜ 11.0.23

osv

org.apache.tomcat

tomcat

generic

≥ 7.0.100 and ≤ 7.0.109 · ≥ 8.5.38 and ≤ 8.5.100 · ≥ 9.0.13 and ＜ 9.0.119 · ≥ 10.1.0 and ＜ 10.1.56 · ≥ 11.0.0 and ＜ 11.0.23

osv

org.apache.tomcat

tomcat-tribes

generic

≥ 7.0.100 and ≤ 7.0.109 · ≥ 8.5.38 and ≤ 8.5.100 · ≥ 9.0.13 and ＜ 9.0.119 · ≥ 10.1.0 and ＜ 10.1.56 · ≥ 11.0.0 and ＜ 11.0.23

References

URL	Tags
https://github.com/apache/tomcat/commit/3a9ff01d2dfaca651edacbda3260e37b98b540d3	WEB
https://github.com/apache/tomcat/commit/5e594400c7f6ac0eaf2526bd64442a70f5ccaace	WEB
https://github.com/apache/tomcat/commit/6a7a432cd7fb4ef358dc12e8da99cf3ab320f3fe	WEB
https://github.com/apache/tomcat	PACKAGE
https://lists.apache.org/thread/g4p5sf45p3f9r011pwqs9r54yd64s106	WEB
https://tomcat.apache.org/security-10.html	WEB
https://tomcat.apache.org/security-11.html	WEB
https://tomcat.apache.org/security-9.html	WEB
http://www.openwall.com/lists/oss-security/2026/06/29/24	WEB

URL

Timeline

Published	2026-06-29	By the CVE Program.
NVD record modified	2026-10-25	NVD's own last-modified date for this record.

Published

2026-06-29

By the CVE Program.

NVD record modified

2026-10-25

NVD's own last-modified date for this record.

How VRT decided (17 of 24 rules ran)

17 of 24 rules ran. The rest didn't run because an earlier rule had already settled the CVE.

# Rule Outcome Status Detail

identity: Does this identifier describe a vulnerability at all? the first rule that matches decides

1 rejected no match CVE Program withdrawal of this identifier

scope: Is it a vulnerability Waratek protects? the first rule that matches decides

2 armr-patch-file no match An ARMR patch file on disk for this CVE

3 armr-secure-rule-file no match An ARMR security-rule template on disk for this CVE

4 manual-classification no match A researcher's recorded decision for this specific CVE

5 manual classification no match Manual classification of this CVE in the legacy dataset

6 non-java-upstream no match A root cause in non-Java code: an OS kernel, a C library, or a bundled runtime

7 oracle-component no match The defect being in a component of a tracked product the agent does not reach: JavaFX, the Java SE installer, the JInitiator browser plug-in, the native WebLogic proxy plug-in, or a native part of Oracle Application Server or Collaboration Suite (HTTP Server, Web Cache, Internet Directory, mail and calendar servers). Oracle gives these no CPE of their own and names them only in the description.

8 java-client-side no match Oracle's own risk-matrix note saying the CVE is reached only through untrusted code in the Java sandbox (applets, Web Start) or only through a client installation of Java, so a server running its own trusted code is not exposed

9 osv-maven matched In scope Maven packages: org.apache.tomcat:tomcat, org.apache.tomcat:tomcat-tribes

10 cna-maven-package not reached An affected Maven artifact named by the CNA itself

11 known-cpe-product not reached An NVD CPE naming a product ARMR tracks

12 cna-cpe-product not reached A CPE the CNA published naming a tracked product. Oracle publishes these on advisory day, months before NVD.

13 oracle-advisory-family not reached A tracked product family named in Oracle's own risk matrix. CPE cannot carry a suite name, only a module.

14 cna-named-product not reached A tracked product named in words by the CVE's own CNA, on a record with no CPE yet. Apache and Eclipse publish these on advisory day, before NVD adds CPE data.

15 non-deployable-product not reached The only affected product being a sealed appliance image, where Java runs but no -javaagent can be attached

16 unmatched-product not reached No tracked product matched above, and none present at all

disposition: What do we do about one that is? every rule runs

17 patch-hint no match A reference pointing at the upstream fix: a commit, a PR, a Red Hat bug

18 open-source-maven matched Mitigation candidate Open-source Maven artifact indexed by OSV (Maven packages: org.apache.tomcat:tomcat, org.apache.tomcat:tomcat-tribes). The source is public, which makes an ARMR patch rule a candidate; nothing here establishes that one can be written.

19 poc-derivable skipped An indexed exploit clearing the evidence bar to reverse-engineer, where there is no source to read

20 no-exploit skipped Nothing to build a rule from yet: no published exploit, no CISA record of exploitation and no source-level change to read

21 secure-rule-match no match A vulnerability class already blocked by an ARMR security rule

22 exploited-no-fix-or-poc skipped Somebody exploiting this CVE (a CISA or VulnCheck KEV listing, or a CISA verdict of active exploitation), with no fix, source code or PoC to build a rule from

23 below-action-threshold withheld CVE ships in Oracle Critical Patch Update October 2026, Oracle Critical Security Patch Update August 2026, Oracle Critical Security Patch Update September 2026 (CPU) — Oracle treats it as urgent, so severity does not settle it

24 no-exploit-published decided it matched No exploit published No exploit code has been published, and an upstream fix path does exist, so the remediation half of the candidacy still holds.

Products the scope rules checked

The products this CVE's record names, and whether VRT tracks each one. The scope rules decided on these.

Vendor Product Tracked CPE Source

apache tomcat tracked cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:* yaml

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