CVE-2026-43512: Apache Tomcat: Digest authenticator will authenticate any unknown user

[Mark Thomas <markt () apache org>]

Severity: moderate

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 8.5.0 through 8.5.100
- Apache Tomcat 7.0.0 through 7.0.109
- Apache Tomcat before 7.0.0 unknown

Description:

DEPRECATED: Authentication Bypass Issues vulnerability in digest 
authentication 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 8.5.0 
through 8.5.100, from before 7.0.0.
Older unsupported versions any also be affect

Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 
which fix the issue.

References:

https://lists.apache.org/thread/7x09x7o12solvclslw3sz0288xc8wx73
https://tomcat.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-43512