Improper Certificate Validation in Apache Tomcat - CVE-2026-53434
Published: June 30, 2026
Vulnerability identifier: #VU135865
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-2026-53434
CWE-ID: CWE-295
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 with an invalid certificate.
The vulnerability exists due to improper certificate revocation validation in the FFM Connector when handling connections with invalid CRL configuration. A remote attacker can present an invalid certificate to authenticate with an invalid certificate.
Only configurations using the FFM Connector with invalid CRLs are affected.
How to mitigate CVE-2026-53434
Install security update from vendor's website.
Sources
- https://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.1.56
- https://tomcat.apache.org/security-11.html#Fixed_in_Apache_Tomcat_11.0.23
- https://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.119
- https://github.com/apache/tomcat/commit/feec60d6099727db6f911534f6a0f6926ebab070