CVE-2026-6412 in wolfSSL
Summary
by MITRE • 06/26/2026
Certificate policy and RFC 8446 compliance concerns regarding the continued acceptance of SHA-1/MD5 in certificate processing.
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Analysis
by VulDB Data Team • 06/26/2026
The vulnerability stems from the continued acceptance of SHA-1 and MD5 cryptographic hash functions within certificate processing systems despite their well-documented security weaknesses and industry consensus against their use. This issue represents a fundamental compliance failure with both RFC 8446 (TLS 1.3) specifications and established certificate policy frameworks that mandate the use of secure cryptographic algorithms. The persistence of SHA-1 and MD5 acceptance creates significant operational risks as these hash functions are vulnerable to collision attacks, making them susceptible to certificate forgery and man-in-the-middle attacks. According to CWE-327, the use of weak cryptographic algorithms directly violates security best practices and creates exploitable weaknesses in cryptographic implementations. The continued acceptance of these deprecated algorithms in certificate processing systems undermines the integrity of public key infrastructure and exposes organizations to potential credential compromise.
The technical flaw manifests in certificate validation processes that fail to properly enforce cryptographic strength requirements during certificate chain verification. When certificate authorities or validation systems accept certificates signed with SHA-1 or MD5 hashes, they create a security vulnerability that can be exploited by attackers to generate fraudulent certificates that appear legitimate. This weakness particularly impacts TLS implementations where certificate validation is critical for establishing secure communications. The flaw operates at the intersection of certificate policy enforcement and cryptographic algorithm selection, where systems fail to properly validate that certificates meet minimum security requirements defined in RFC 8446 and related standards. Attackers can leverage this vulnerability to perform hash collision attacks against SHA-1 signed certificates, potentially creating forged certificates that bypass validation checks.
The operational impact of this vulnerability extends beyond immediate security risks to encompass regulatory compliance failures and potential legal consequences for organizations that continue to accept weak cryptographic signatures. Industry frameworks such as NIST SP 800-131A explicitly prohibit the use of SHA-1 and MD5 in cryptographic applications, making continued acceptance a violation of established security standards. Organizations relying on systems that permit SHA-1/MD5 certificate processing face potential compromise of their entire security infrastructure, particularly when these systems handle sensitive data or serve as trust anchors for other security mechanisms. The vulnerability creates persistent exposure windows where attackers can exploit the weakness to establish unauthorized secure connections or impersonate legitimate services.
Mitigation strategies must focus on immediate enforcement of cryptographic algorithm policies and comprehensive system updates to eliminate support for SHA-1 and MD5 hash functions. Organizations should implement strict certificate policy enforcement that rejects any certificates signed with weak cryptographic algorithms, ensuring compliance with RFC 8446 requirements and industry best practices. System administrators must conduct thorough inventory assessments to identify all components that may still accept legacy hash functions and implement remediation procedures including certificate revocation and algorithm upgrades. Security frameworks such as those defined in the MITRE ATT&CK matrix categorize this vulnerability under credential access and defense evasion techniques, emphasizing the need for proactive security measures. Regular security audits should verify compliance with cryptographic strength requirements and ensure that all certificate validation processes properly enforce minimum security standards to prevent exploitation of these known weaknesses.