---
id: CVE-2026-55957
aliases:
  - GHSA-7895-gffq-w6jq
title: Apache Tomcat has a Missing Critical Step in Authentication vulnerability
summary: Apache Tomcat has a Missing Critical Step in Authentication vulnerability
severity: high
cvss: 7.3
cwe:
  - CWE-304
vendor: apache
product: 'org.apache.tomcat.embed:tomcat-embed-core'
ecosystem: maven
affected:
  - 'org.apache.tomcat.embed:tomcat-embed-core >= 11.0.0-M1, < 11.0.5'
  - 'org.apache.tomcat.embed:tomcat-embed-core >= 10.1.0-M1, < 10.1.37'
  - 'org.apache.tomcat.embed:tomcat-embed-core >= 9.0.0.M1, < 9.0.101'
  - 'org.apache.tomcat.embed:tomcat-embed-core >= 8.5.0, <= 8.5.100'
  - 'org.apache.tomcat.embed:tomcat-embed-core <= 7.0.109'
  - 'org.apache.tomcat:tomcat >= 11.0.0-M1, < 11.0.5'
  - 'org.apache.tomcat:tomcat >= 10.1.0-M1, < 10.1.37'
  - 'org.apache.tomcat:tomcat >= 9.0.0.M1, < 9.0.101'
  - 'org.apache.tomcat:tomcat >= 8.5.0, <= 8.5.100'
  - 'org.apache.tomcat:tomcat <= 7.0.109'
  - 'org.apache.tomcat:tomcat-catalina >= 11.0.0-M1, < 11.0.5'
  - 'org.apache.tomcat:tomcat-catalina >= 10.1.0-M1, < 10.1.37'
  - 'org.apache.tomcat:tomcat-catalina >= 9.0.0.M1, < 9.0.101'
  - 'org.apache.tomcat:tomcat-catalina >= 8.5.0, <= 8.5.100'
  - 'org.apache.tomcat:tomcat-catalina <= 7.0.109'
patched:
  - 'org.apache.tomcat.embed:tomcat-embed-core 11.0.5'
  - 'org.apache.tomcat.embed:tomcat-embed-core 10.1.37'
  - 'org.apache.tomcat.embed:tomcat-embed-core 9.0.101'
  - 'org.apache.tomcat:tomcat 11.0.5'
  - 'org.apache.tomcat:tomcat 10.1.37'
  - 'org.apache.tomcat:tomcat 9.0.101'
  - 'org.apache.tomcat:tomcat-catalina 11.0.5'
  - 'org.apache.tomcat:tomcat-catalina 10.1.37'
  - 'org.apache.tomcat:tomcat-catalina 9.0.101'
published: '2026-06-29'
updated: '2026-11-04'
sourceUpdated: '2026-11-04T16:22:00Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-7895-gffq-w6jq'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55957'
  - url: 'https://lists.apache.org/thread/7fk339o5jvd4mcgsf0chbrn4o525ccjh'
  - url: 'http://www.openwall.com/lists/oss-security/2026/06/29/26'
  - url: >-
      https://github.com/apache/tomcat/commit/0cd21c0393b8811af22daddbba7b4e7328e2d79e
  - url: >-
      https://github.com/apache/tomcat/commit/c32bbd37ea9ee0aaab848af4ee1c9a76e84240ea
  - url: >-
      https://github.com/apache/tomcat/commit/fd96ab415631eea44636c94f911dd38427070ef9
  - url: 'https://tomcat.apache.org/security-10.html'
  - url: 'https://tomcat.apache.org/security-11.html'
  - url: 'https://tomcat.apache.org/security-9.html'
  - url: 'https://github.com/advisories/GHSA-7895-gffq-w6jq'
tags:
  - ghsa
  - maven
  - exploit-available
epss: 0.02855
epssPercentile: 0.86771
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/mdvpat/CVE-2026-55957-PoC'
  checkedAt: '2026-11-05T15:45:35.632Z'
exploitAvailable: true
ingestedAt: '2026-11-04T17:19:45.136Z'
---

## Overview

Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without providing the correct password.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109.

Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.

## Affected packages

- `org.apache.tomcat.embed:tomcat-embed-core >= 11.0.0-M1, < 11.0.5`
- `org.apache.tomcat.embed:tomcat-embed-core >= 10.1.0-M1, < 10.1.37`
- `org.apache.tomcat.embed:tomcat-embed-core >= 9.0.0.M1, < 9.0.101`
- `org.apache.tomcat.embed:tomcat-embed-core >= 8.5.0, <= 8.5.100`
- `org.apache.tomcat.embed:tomcat-embed-core <= 7.0.109`
- `org.apache.tomcat:tomcat >= 11.0.0-M1, < 11.0.5`
- `org.apache.tomcat:tomcat >= 10.1.0-M1, < 10.1.37`
- `org.apache.tomcat:tomcat >= 9.0.0.M1, < 9.0.101`
- `org.apache.tomcat:tomcat >= 8.5.0, <= 8.5.100`
- `org.apache.tomcat:tomcat <= 7.0.109`
- `org.apache.tomcat:tomcat-catalina >= 11.0.0-M1, < 11.0.5`
- `org.apache.tomcat:tomcat-catalina >= 10.1.0-M1, < 10.1.37`
- `org.apache.tomcat:tomcat-catalina >= 9.0.0.M1, < 9.0.101`
- `org.apache.tomcat:tomcat-catalina >= 8.5.0, <= 8.5.100`
- `org.apache.tomcat:tomcat-catalina <= 7.0.109`

## Remediation

Upgrade to a patched release:

- `org.apache.tomcat.embed:tomcat-embed-core 11.0.5`
- `org.apache.tomcat.embed:tomcat-embed-core 10.1.37`
- `org.apache.tomcat.embed:tomcat-embed-core 9.0.101`
- `org.apache.tomcat:tomcat 11.0.5`
- `org.apache.tomcat:tomcat 10.1.37`
- `org.apache.tomcat:tomcat 9.0.101`
- `org.apache.tomcat:tomcat-catalina 11.0.5`
- `org.apache.tomcat:tomcat-catalina 10.1.37`
- `org.apache.tomcat:tomcat-catalina 9.0.101`