The vulnerability arises when the OpenSSLLifecycleListener in Apache Tomcat is configured to activate Java FIPS mode but the underlying FIPS initialization fails. Instead of halting startup, Tomcat logs an error and then continues to use the default JSSE provider in non‑FIPS mode. This failure‑securely behavior is classified as CWE‑636. The failure also logs details that could expose sensitive information, reflecting CWE‑455. As a result, applications that rely on the listener to enforce stricter cryptographic requirements will end up operating with weaker, non‑FIPS compliant cipher suites, potentially exposing data to cryptanalytic attacks.

The affected software is Apache Tomcat in its 9.x, 10.x, and 11.x branches. Vulnerable releases include Tomcat 9.0.92 through 9.0.122, Tomcat 10.1.22 through 10.1.60, and Tomcat 11.0.0‑M14 through 11.0.26. Users are advised to upgrade to Tomcat 9.0.123, 10.1.61, or 11.0.27, which incorporate the fix that forces startup to fail if FIPS initialization fails.

With a CVSS score of 6.5, the issue is considered of moderate severity. The EPSS score is reported as less than 1 %, indicating that widespread exploitation is unlikely at present, and the vulnerability is not listed in CISA’s KEV catalog. The primary attack vector would require an attacker or internal user to modify the Tomcat configuration to enable the OpenSSLLifecycleListener with FIPS mode enabled. Based on the description, it is inferred that an attacker could leverage the unintended fallback to weaker cryptography, but direct harm would still depend on the specific application and environment. Therefore, the overall risk is moderate, and the likelihood of exploitation remains low.