CVE-2025-66614: apache software foundation apache tomcat Improper Input Validation

Vulnerability summary

CVE-2025-66614 is a critical (CVSS 9.1) Improper Input Validation vulnerability in apache software foundation apache tomcat. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18.5% of scored vulnerabilities.

Timeline

1. 17-02-2026
   PublishedVulnerability first disclosed.
2. 24-03-2026
   Last modifiedVulnerability information updated.

Description

Improper Input Validation vulnerability. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.14, from 10.1.0-M1 through 10.1.49, from 9.0.0-M1 through 9.0.112. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 through 8.5.100. Older EOL versions are not affected. Tomcat did not validate that the host name provided via the SNI extension was the same as the host name provided in the HTTP host header field. If Tomcat was configured with more than one virtual host and the TLS configuration for one of those hosts did not require client certificate authentication but another one did, it was possible for a client to bypass the client certificate authentication by sending different host names in the SNI extension and the HTTP host header field. The vulnerability only applies if client certificate authentication is only enforced at the Connector. It does not apply if client certificate authentication is enforced at the web application. Users are recommended to upgrade to version 11.0.15 or later, 10.1.50 or later or 9.0.113 or later, which fix the issue.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
• CWE-295Improper Certificate ValidationThe product does not validate, or incorrectly validates, a certificate.