CVE-2026-74048 in Tomcat
Summary
by MITRE • 10/20/2026
Not Failing Securely ('Failing Open') vulnerability in Apache Tomcat. If the OpenSSLLifecycleListener is configured to use FIPS mode but FIPS activation fails, Tomcat logs and error but continues to use JSSE in non-FIPS mode with the provided configuration.
This issue affects Apache Tomcat: from 11.0.0-M14 through 11.0.26, from 10.1.22 through 10.1.60, from 9.0.92 through 9.0.122.
Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fix the issue.
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Analysis
by VulDB Data Team • 10/20/2026
The vulnerability identified in Apache Tomcat represents a critical security flaw categorized as failing open, where the application continues operation with reduced security controls rather than terminating when a required security mechanism fails to initialize. Specifically, this issue resides within the OpenSSLLifecycleListener component, which is responsible for configuring OpenSSL-based SSL/TLS connections and enforcing Federal Information Processing Standards (FIPS) compliance. When an administrator configures Tomcat to operate in FIPS mode, they are asserting that all cryptographic operations must adhere to strict government-approved standards designed to protect sensitive data against advanced threats. However, if the underlying system fails to activate this FIPS mode due to missing libraries, incorrect configuration, or environmental constraints, the listener does not halt service as it should. Instead, it logs an error and proceeds to use Java Secure Socket Extension (JSSE) in standard non-FIPS mode with the provided configuration. This behavior creates a dangerous state where security policies appear to be enforced based on configuration files, but are effectively bypassed at runtime without explicit warning to the operator that compliance has been lost.
From a technical perspective, this flaw stems from an insufficient error handling mechanism within the lifecycle listener logic. The code path assumes that if FIPS activation fails, the fallback behavior of using JSSE is acceptable or transparent enough not to compromise security posture. In reality, this assumption violates the principle of least privilege and secure failure modes. By continuing with non-FJSSE mode, Tomcat may utilize cryptographic algorithms or key lengths that are prohibited under FIPS 140-2 or FIPS 140-3 standards. This discrepancy means that applications relying on Tomcat for regulatory compliance, such as those in finance, healthcare, or government sectors, could inadvertently process sensitive data using non-compliant encryption methods. The lack of a hard failure state makes it difficult for security monitoring tools to detect the downgrade automatically, potentially allowing attackers to exploit weaker cryptographic implementations if they can influence traffic interception scenarios where FIPS-specific protections would have otherwise prevented certain attacks.
The operational impact of this vulnerability is significant for organizations requiring strict adherence to federal or industry-standard encryption protocols. For entities subject to regulations like PCI-DSS, HIPAA, or NIST guidelines that mandate FIPS 140-2 validated modules, this flaw effectively nullifies their compliance efforts if the failure goes unnoticed. An attacker who can perform a man-in-the-middle attack might exploit weaker cipher suites available in non-FIPS mode, potentially decrypting traffic that was assumed to be protected by stronger, standardized algorithms. Furthermore, because the error is merely logged and not fatal, system administrators may remain unaware of the security degradation for extended periods. This stealthy nature increases the window of exposure and complicates incident response efforts, as forensic analysis might reveal compliant configurations in logs while actual runtime behavior was non-compliant.
To mitigate this risk, organizations must immediately upgrade Apache Tomcat to version 11.0.27, 10.1.61, or 9.0.123, depending on their current deployment branch. These versions correct the lifecycle listener logic to ensure that any failure in FIPS activation results in a fatal error, thereby preventing the server from starting with insecure cryptographic defaults. In addition to upgrading, administrators should verify their environment meets all prerequisites for FIPS mode operation, including ensuring that compatible OpenSSL libraries are installed and correctly linked. It is also advisable to implement robust monitoring alerts specifically targeting SSL/TLS initialization errors during startup sequences. By treating these errors as critical events rather than informational logs, security teams can ensure that any deviation from the intended secure configuration triggers an immediate investigation before production traffic begins flowing over potentially compromised channels. This approach aligns with industry best practices for secure system design and helps maintain integrity against CWE-254, which classifies failures to enforce required security properties during error conditions.