CVE-2026-53434 Apache Software Foundation CVE debrief

Who should care

Defenders and administrators of Apache Tomcat instances should assess exposure and prioritize upgrading to fixed versions. Affected operators, platforms, and security teams should review and update affected versions. Vulnerability management and security teams should verify certificate validation configurations and assess exposure of affected versions.

Why it matters

Defenders should care about this vulnerability as it affects Apache Tomcat instances and could allow invalid certificates to be accepted. Affected versions require verification and upgrading to fixed versions is recommended.

• Verify certificate validation configurations
• Assess exposure of affected versions
• Prioritize upgrading to fixed versions
• Review CRL configurations for FFM based connectors

Technical summary

Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring Certificate Revocation List (CRLs) for a FFM based connector. If an FFM connector was configured with invalid CRLs, the invalid CRLs were ignored meaning invalid certificates could be accepted. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M7 through 10.1.55, from 9.0.83 through 9.0.118. Users are recommended to upgrade to version 11.0.23, 10.1.56 or 9.0.119, which fixes the issue. The vulnerability requires verification and upgrading to fixed versions is recommended.

Defensive priority

Upgrade to fixed versions and verify CRL configurations

Recommended defensive actions

• Upgrade to Apache Tomcat version 11.0.23, 10.1.56, or 9.0.119
• Verify CRL configurations for FFM based connectors
• Review and update affected versions
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The vulnerability affects Apache Tomcat versions from 11.0.0-M1 through 11.0.22, from 10.1.0-M7 through 10.1.55, and from 9.0.83 through 9.0.118. Users are recommended to upgrade to version 11.0.23, 10.1.56, or 9.0.119, which fixes the issue. Evidence is limited to supplied source details and CVE record information. Defenders should verify certificate validation configurations and assess exposure of affected versions.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.