Various CVEs for Tomcat (all versions) reported today. Please consider
upgrading at your earliest convenience.
---------- Forwarded message ---------
From: Mark Thomas <markt@xxxxxxxxxx>
Date: Tue, May 12, 2026 at 9:21 AM
Subject: [SECURITY] CVE-2026-43512 Apache Tomcat - Digest authenticator
will authenticate any unknown user
To: Tomcat Users List <users@xxxxxxxxxxxxxxxxx>, announce@xxxxxxxxxxxxxxxxx
<announce@xxxxxxxxxxxxxxxxx>, <announce@xxxxxxxxxx>, Tomcat Developers List
<dev@xxxxxxxxxxxxxxxxx>
CVE-2026-43512 Apache Tomcat - Digest authenticator will authenticate
any unknown user
Severity: Moderate
Vendor: The Apache Software Foundation
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
History:
2026-05-12 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
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Jennifer Oxelson Ganter NSF Unidata
Software Engineer IV P.O. Box 3000
oxelson@xxxxxxxx Boulder, CO 80307
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