CVE-2025-66567

Critical

Published: 09/12/2025(UTC)Translated: 05/08/2026(UTC)NVD NIST

Summary

The ruby-saml library up to version 1.12.4 contains an authentication bypass vulnerability due to an incomplete fix for CVE-2025-25292. Differences in XML parsing between ReXML and Nokogiri allow an attacker to perform a Signature Wrapping attack. The issue is fixed in version 1.18.0.

Risk Assessment

An attacker can bypass SAML authentication and gain unauthorized access to systems using ruby-saml, potentially leading to account takeover or privilege escalation.

Recommendation

Immediately upgrade ruby-saml to version 1.18.0 or later to remediate the vulnerability.

Original NVD description (English source)

The ruby-saml library is for implementing the client side of a SAML authorization. ruby-saml versions up to and including 1.12.4 contain an authentication bypass vulnerability due to an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, generating entirely different document structures from the same input. This allows an attacker to execute a Signature Wrapping attack. This issue is fixed in version 1.18.0.