CVE-2026-77791 PUBLISHED

Apache Tomcat: DoS via busy wait during WebSocket close

Assigner: apache
Reserved: 21.08.2026 Published: 23.09.2026 Updated: 23.09.2026

Uncontrolled Resource Consumption vulnerability in Apache Tomcat during sending of WebSocket close message enabled a DoS attack.

This issue affects Apache Tomcat: from 11.0.0-M5 through 11.0.25, from 10.1.8 through 10.1.59, from 9.0.74 through 9.0.121.

The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.88 through 8.5.100. 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.

Product Status

Vendor Apache Software Foundation
Product Apache Tomcat
Versions Default: unaffected
  • affected from 11.0.0-M5 to 11.0.25 (incl.)
  • affected from 10.1.8 to 10.1.59 (incl.)
  • affected from 9.0.74 to 9.0.121 (incl.)
  • affected from 8.5.88 to 8.5.100 (incl.)
  • unaffected from 0 to 7.0.109 (incl.)

References

Problem Types

  • CWE-400 Uncontrolled Resource Consumption CWE