---
id: CVE-2026-76183
title: >-
  Authentication Bypass by Alternate Name vulnerability in Apache Tomcat allowed
  the security constraints for any WebSocket endpoint to be bypassed.




  This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from
  10.1.0-M1 throug…
summary: >-
  Authentication Bypass by Alternate Name vulnerability in Apache Tomcat allowed
  the security constraints for any WebSocket endpoint to be bypassed.




  This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from
  10.1.0-M1 throug…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-289
vendor: Apache Software Foundation
product: Apache Tomcat
affected:
  - apache_tomcat >= 11.0.0-M1 <= 11.0.25
  - apache_tomcat >= 10.1.0-M1 <= 10.1.59
  - apache_tomcat >= 9.0.0.M1 <= 9.0.121
  - apache_tomcat >= 8.5.0 <= 8.5.100
  - apache_tomcat >= 7.0.43 <= 7.0.109
patched:
  - hardened_images
published: '2026-09-23'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T15:22:34.470'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76183'
references:
  - url: 'https://lists.apache.org/thread/45mxk8nj2q8pkhct6lfxkvtm2jpywrsp'
    label: security@apache.org
  - url: 'http://www.openwall.com/lists/oss-security/2026/09/23/21'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76183.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-76183'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2539355'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-76183'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-76183'
  - url: 'https://access.redhat.com/errata/RHSA-2026:68257'
  - url: 'https://access.redhat.com/errata/RHSA-2026:68258'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
  - exploit-available
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-09-23T15:33:34.949308Z'
epss: 0.00566
epssPercentile: 0.46821
scores:
  nvd: 9.8
  vendor: 7.4
  adp: 9.8
ingestedAt: '2026-09-23T11:22:32.916Z'
exploits:
  github: 1
  githubRepos:
    - 'https://github.com/Ethen1212/tomcat-CVE-2026-76183'
  checkedAt: '2026-10-27T19:12:25.822Z'
exploitAvailable: true
---

## Overview

Authentication Bypass by Alternate Name vulnerability in Apache Tomcat allowed the security constraints for any WebSocket endpoint to be bypassed.



This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M1 through 9.0.121.



The following versions were EOS at the time the CVE was created but are 
known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through 7.0.109. Other unsupported versions may also be affected.




Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:68257** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68257)
- **RHSA-2026:68258** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68258)
- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat JBoss Web Server 5, Red Hat JBoss Web Server 6, … · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat JBoss Web Server 5, … · updated 2026-10-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-76183.json)