CVE-2026-76183: CWE-289 Authentication Bypass by Alternate Name in Apache Software Foundation Apache Tomcat
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.
AI Analysis
Technical Summary
CVE-2026-76183 is a CWE-289 Authentication Bypass vulnerability in Apache Tomcat that allows attackers to bypass security constraints on WebSocket endpoints by leveraging an alternate name mechanism. This flaw affects a broad range of Apache Tomcat versions, including recent and some end-of-support releases. The vulnerability permits unauthorized access to WebSocket endpoints that should be protected by authentication controls. The Apache Software Foundation has addressed this issue in versions 11.0.26, 10.1.60, and 9.0.122.
Potential Impact
The vulnerability enables attackers to bypass authentication controls on WebSocket endpoints, potentially allowing unauthorized access to restricted resources or functionality within affected Apache Tomcat servers. This could lead to unauthorized actions or data exposure on systems relying on WebSocket security constraints.
Mitigation Recommendations
Users should upgrade affected Apache Tomcat instances to versions 11.0.26, 10.1.60, or 9.0.122, which contain fixes for this authentication bypass vulnerability. No other mitigations are indicated by the vendor advisory. Applying these official updates is the recommended remediation.
CVE-2026-76183: CWE-289 Authentication Bypass by Alternate Name in Apache Software Foundation Apache Tomcat
Description
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.
CVSS v3.1
Score 9.8critical
Affected software
Apache Software Foundation
Apache Tomcat
pkg:maven/org.apache.tomcat/tomcatRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-76183 is a CWE-289 Authentication Bypass vulnerability in Apache Tomcat that allows attackers to bypass security constraints on WebSocket endpoints by leveraging an alternate name mechanism. This flaw affects a broad range of Apache Tomcat versions, including recent and some end-of-support releases. The vulnerability permits unauthorized access to WebSocket endpoints that should be protected by authentication controls. The Apache Software Foundation has addressed this issue in versions 11.0.26, 10.1.60, and 9.0.122.
Potential Impact
The vulnerability enables attackers to bypass authentication controls on WebSocket endpoints, potentially allowing unauthorized access to restricted resources or functionality within affected Apache Tomcat servers. This could lead to unauthorized actions or data exposure on systems relying on WebSocket security constraints.
Mitigation Recommendations
Users should upgrade affected Apache Tomcat instances to versions 11.0.26, 10.1.60, or 9.0.122, which contain fixes for this authentication bypass vulnerability. No other mitigations are indicated by the vendor advisory. Applying these official updates is the recommended remediation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-08-19T10:37:56.319Z
- State
- PUBLISHED
Threat ID: 6ab3b90df7a7c54106b30f1b
Added to database: 09/23/2026, 11:33:33 UTC
Last enriched: 09/23/2026, 11:48:17 UTC
Last updated: 09/24/2026, 02:59:28 UTC
Views: 63
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