CVE-2026-87022 PUBLISHED

Apache Tomcat: WebSocket message smuggling with per-message-deflate

Assigner: apache
Reserved: 08.09.2026 Published: 23.09.2026 Updated: 23.09.2026

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.

Product Status

Vendor Apache Software Foundation
Product Apache Tomcat
Versions Default: unaffected
  • affected from 11.0.0-M1 to 11.0.25 (incl.)
  • affected from 10.1.0-M1 to 10.1.59 (incl.)
  • affected from 9.0.0.M1 to 9.0.121 (incl.)
  • affected from 8.5.0 to 8.5.100 (incl.)
  • affected from 7.0.56 to 7.0.109 (incl.)

Credits

  • krsecurity(kongr) finder

References

Problem Types

  • CWE-130 Improper handling of length parameter inconsistency CWE