CVE-2026-43512: Apache Tomcat - Digest authenticator will authenticate any unknown user
(updated )
Versions Affected: Apache Tomcat 11.0.0-M1 to 11.0.21 Apache Tomcat 10.1.0-M1 to 10.1.54 Apache Tomcat 9.0.0.M1 to 9.0.117 Older, unsupported versions may also be affected
Description: When DIGEST authentication was configured, any user not known to the configured Realm would be authenticated if they presented the password “null”.
Mitigation: Users of the affected versions should apply one of the following mitigations:
- Upgrade to Apache Tomcat 11.0.22 or later
- Upgrade to Apache Tomcat 10.1.55 or later
- Upgrade to Apache Tomcat 9.0.118 or later
References
- github.com/advisories/GHSA-h6fc-48rj-7qqh
- github.com/apache/tomcat/commit/3d4d3fae07a6cd9c2eb193c5491001740ec64448
- github.com/apache/tomcat/commit/6565a6cb6499e56fe2f34457cec99f9d1c4f39e9
- github.com/apache/tomcat/commit/a99c355e8199adbfd67c9a1fffbd85b810b196cd
- lists.apache.org/thread/7x09x7o12solvclslw3sz0288xc8wx73
- nvd.nist.gov/vuln/detail/CVE-2026-43512
- tomcat.apache.org/security-10.html
- tomcat.apache.org/security-11.html
- tomcat.apache.org/security-9.html
Code Behaviors & Features
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