CVE-2026-76183: Authentication Bypass by Alternate Name

September 23, 2026 (updated September 30, 2026)

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.

References

github.com/apache/tomcat/commit/e182d86b7d4cc19ec4c24c38f37acc004404fe8e
lists.apache.org/thread/45mxk8nj2q8pkhct6lfxkvtm2jpywrsp
nvd.nist.gov/vuln/detail/CVE-2026-76183

Code Behaviors & Features

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