CVE-2026-86350 Apache Tomcat - Regression in fix for CVE-2026-41293 can
trigger request header mix-up
Severity: Important
Vendor: The Apache Software Foundation
Versions Affected:
Apache Tomcat 11.0.22 to 11.0.25
Apache Tomcat 10.1.55 to 10.1.59
Apache Tomcat 9.0.118 to 9.0.121
Description:
Inconsistent interpretation of HTTP/2 requests caused by a regression in
fix for CVE-2026-41293 can trigger request header mix-up.
Mitigation:
Users of the affected versions should apply one of the following
mitigations:
- Remove the examples web application
- Upgrade to Apache Tomcat 11.0.26
- Upgrade to Apache Tomcat 10.1.60
- Upgrade to Apache Tomcat 9.0.122
Credit:
This issue was identified by:
- Jeppe Weikop
History:
2026-09-23 Original advisory
References:
[1] https://tomcat.apache.org/security-11.html
[2] https://tomcat.apache.org/security-10.html
[3] https://tomcat.apache.org/security-9.html
