CVE-2026-41293: Apache Tomcat: HTTP/2 request headers not validated

[Mark Thomas <markt () apache org>]

Severity: low

Affected versions:

- Apache Tomcat 11.0.0-M1 through 11.0.21
- Apache Tomcat 10.1.0-M1 through 10.1.54
- Apache Tomcat 9.0.0.M1 through 9.0.117
- Apache Tomcat 10.0.0-M1 through 10.0.27
- Apache Tomcat 8.5.0 through 8.5.100

Description:

Improper Input Validation vulnerability in Apache Tomcat.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 
10.1.0-M1 through 10.1.54, from 9.0.0.M1 through 9.0.117, from 10.0.0-M1 
through 10.0.27.
Older, end of support versions may also be affected.

Users are recommended to upgrade to version [FIXED_VERSION], which fixes 
the issue.

Credit:

Dawit Jeong (@dawitngoliath) (finder)

References:

https://lists.apache.org/thread/qwg0q16z7xkb2qrr853wdll5531mvl1r
https://tomcat.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-41293