CVE-2026-78437 PUBLISHED

Apache Tomcat: HTTP/2 DoS via malformed request

Assigner: apache
Reserved: 24.08.2026 Published: 23.09.2026 Updated: 23.09.2026

Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail.

This issue affects Apache Tomcat: from 11.0.19 through 11.0.25, from 10.1.53 through 10.1.59, from 9.0.116 through 9.0.121.

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 11.0.19 to 11.0.25 (incl.)
  • affected from 10.1.53 to 10.1.59 (incl.)
  • affected from 9.0.116 to 9.0.121 (incl.)
  • unaffected from 0 to 8.5.100 (incl.)

References

Problem Types

  • CWE-459 Incomplete cleanup CWE