Improper Authentication in Apache Tomcat - CVE-2026-43512
Published: May 12, 2026
Vulnerability identifier: #VU131180
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-43512
CWE-ID: CWE-287
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Apache Foundation
Affected software:
Apache Tomcat
Apache Tomcat
Detailed vulnerability description
The vulnerability allows a remote attacker to authenticate as an unknown user.
The vulnerability exists due to improper authentication in the DIGEST authenticator when processing authentication for users not known to the configured Realm. A remote attacker can submit the password "null" for an unknown user to authenticate as an unknown user.
This occurs only when DIGEST authentication is configured.
How to mitigate CVE-2026-43512
Install security update from vendor's website.