CVE-2026-87022: Improper Handling of Length Parameter Inconsistency

September 23, 2026

Improper handling of length parameter inconsistency vulnerability in Apache Tomcat allows WebSocket message smuggling when per-message-deflate is used.

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 7.0.56 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 9.1.22, which fix the issue.

References

github.com/apache/tomcat/commit/4fef25fe2ab7509e697af093280b9daadb515615
lists.apache.org/thread/ypvlkjqsq0480fnk9jm6h9qllddwlw4w
nvd.nist.gov/vuln/detail/CVE-2026-87022

Code Behaviors & Features

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