CVE-2026-6092 in wolfSSL
Summary
by MITRE • 06/26/2026
When HAVE_ENCRYPT_THEN_MAC is configured, the implementation could fall back to MAC-then-Encrypt rather than enforcing Encrypt-then-MAC.
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Analysis
by VulDB Data Team • 06/28/2026
This vulnerability relates to a critical flaw in cryptographic protocol implementation where the system fails to properly enforce the encrypt-then-mac security model when the HAVE_ENCRYPT_THEN_MAC configuration option is enabled. The issue stems from improper handling of cryptographic operations within TLS implementations, where the system should strictly enforce encrypt-then-mac ordering but instead allows fallback behavior that compromises security assurances.
The technical flaw occurs at the protocol level during handshake and data transmission phases where cryptographic operations are not properly constrained by the configuration parameter. When HAVE_ENCRYPT_THEN_MAC is set, the implementation should mandate that encryption occurs before MAC computation to prevent certain types of attacks including padding oracle attacks and ciphertext manipulation vulnerabilities. However, the flawed implementation permits fallback to the less secure MAC-then-encrypt approach which violates fundamental cryptographic security principles.
This vulnerability creates significant operational impact by weakening the overall security posture of systems relying on the affected cryptographic library or protocol implementation. The fallback behavior exposes systems to authenticated encryption weaknesses that can be exploited by attackers to perform padding oracle attacks, ciphertext modification, and potentially decrypt sensitive information without proper authorization. The security implications extend beyond immediate data confidentiality to encompass integrity protection mechanisms that are essential for secure communication channels.
The vulnerability aligns with CWE-310 which addresses cryptographic issues related to improper implementation of encryption algorithms and key management practices. From an ATT&CK perspective, this weakness maps to techniques involving credential access through cryptographic attacks and privilege escalation via security misconfigurations. The fallback behavior creates opportunities for adversaries to exploit the gap in cryptographic enforcement mechanisms.
Mitigation strategies should focus on ensuring strict enforcement of the encrypt-then-mac ordering regardless of configuration parameters. System administrators must verify that cryptographic libraries properly validate and enforce the intended security model, implementing proper input validation and configuration checks. Regular security audits should validate that cryptographic implementations strictly adhere to established protocols without allowing fallback behaviors that compromise security assurances.
The implementation should incorporate defensive programming practices including mandatory checks at runtime to verify that encryption operations occur before MAC computation. Additionally, logging mechanisms should be enhanced to detect and alert on any attempts to bypass the intended cryptographic ordering, providing visibility into potential security violations. Security testing procedures should include validation of cryptographic protocol adherence specifically targeting the encrypt-then-mac enforcement behavior to prevent similar vulnerabilities in future deployments.
Organizations should consider implementing comprehensive cryptographic policy frameworks that explicitly define and enforce proper encryption ordering requirements while maintaining proper configuration management practices. Regular updates to cryptographic libraries and protocols are essential to ensure that known vulnerabilities are addressed through proper patch management processes, preventing exploitation of implementation weaknesses that could lead to significant security breaches and data compromise incidents.