CVE-2026-76183: Apache Software Foundation Apache Tomcat

Critical severity, CVSS 9.8. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Apache Software Foundation Apache Tomcat: from 11.0.0-M1, up to and including 11.0.25; from 10.1.0-M1, up to and including 10.1.59; from 9.0.0.M1, up to and including 9.0.121; from 8.5.0, up to and including 8.5.100; from 7.0.43, up to and including 7.0.109

Published 2026-09-23. Last modified 2026-09-30.