CVE-2026-53712 in scram
Summary
by MITRE • 07/17/2026
SCRAM (Salted Challenge Response Authentication Mechanism) is part of the family of Simple Authentication and Security Layer (SASL, RFC 4422) authentication mechanisms. Prior to 3.3, a flaw in com.ongres.scram:scram-client and com.ongres.scram:scram-common allows an attacker capable of a TLS man-in-the-middle attack to silently downgrade a connection from SCRAM-SHA-256-PLUS with channel binding to standard SCRAM-SHA-256 without channel binding when TlsServerEndpoint processes an X.509 certificate using a modern signature algorithm such as Ed25519; getChannelBindingData() can return an empty byte array after NoSuchAlgorithmException, and the ScramClient builder treats that as absent channel-binding data. This issue is fixed in version 3.3.
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Analysis
by VulDB Data Team • 07/17/2026
The SCRAM authentication mechanism represents a critical component in securing network communications through challenge-response protocols, forming part of the broader Simple Authentication and Security Layer framework defined in RFC 4422. This vulnerability specifically affects the com.ongres.scram client and common libraries where the implementation fails to properly handle certificate processing under certain TLS conditions. The flaw manifests when a TLS man-in-the-middle attacker can manipulate the authentication flow by forcing a downgrade from a more secure SCRAM-SHA-256-PLUS variant with channel binding to the less secure standard SCRAM-SHA-256 without channel binding.
The technical execution of this vulnerability occurs during the TlsServerEndpoint certificate processing phase when modern signature algorithms like Ed25519 are encountered. When the getChannelBindingData() method encounters a NoSuchAlgorithmException exception, it returns an empty byte array rather than properly handling the cryptographic error. This empty response is then interpreted by the ScramClient builder as the absence of channel binding data, effectively allowing the downgrade to occur without detection. The vulnerability demonstrates a classic security flaw in error handling where an exception condition results in weakened security posture rather than proper failure protection.
This weakness directly impacts the integrity and confidentiality of authentication communications by enabling attackers to silently weaken the security guarantees that channel binding provides. Channel binding serves as a crucial mechanism in preventing replay attacks and ensuring that authentication occurs over the intended secure channel, as outlined in the ATT&CK framework under credential access techniques. The vulnerability essentially undermines the security model established by SCRAM-SHA-256-PLUS, which was specifically designed to provide stronger protection against various attack vectors including man-in-the-middle scenarios.
The operational impact extends beyond simple authentication failure to encompass potential credential compromise and unauthorized system access. Organizations relying on this vulnerable implementation face increased risk of successful authentication bypass attacks where attackers can intercept and manipulate the authentication exchange without detection. This vulnerability aligns with CWE-310 (Cryptographic Issues) and CWE-295 (Improper Certificate Validation), both of which address fundamental weaknesses in cryptographic implementations. The flaw represents a failure in proper error handling protocols that should have maintained security consistency even when encountering unexpected cryptographic conditions.
Mitigation strategies require immediate deployment of version 3.3 or later where the vulnerability has been addressed through improved exception handling and proper channel binding data validation. System administrators should conduct comprehensive inventory assessments to identify all affected implementations and ensure complete patching across all network components utilizing SCRAM authentication. Additionally, organizations should implement monitoring for unauthorized authentication protocol changes and maintain strict certificate validation policies that prevent downgrade attacks. The fix demonstrates the importance of robust error handling in cryptographic libraries where seemingly minor exception conditions can result in significant security implications, reinforcing principles from both NIST SP 800-57 and ISO/IEC 15408 (Common Criteria) security standards.