ADVISORIES

• CVE-2025-25291 (NVD)
• GHSA-4vc4-m8qh-g8jm
• Vendor Advisory

GEM

ruby-saml

PATCHED VERSIONS

• ~> 1.12.4
• >= 1.18.0

DESCRIPTION

Summary

An authentication bypass vulnerability was found in ruby-saml due to a parser differential. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack.

Impact

This issue may lead to authentication bypass.

RELATED

• https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-4vc4-m8qh-g8jm
• https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
• https://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv
• https://nvd.nist.gov/vuln/detail/CVE-2025-25291
• https://github.com/SAML-Toolkits/ruby-saml/commit/e76c5b36bac40aedbf1ba7ffaaf495be63328cd9
• https://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released
• https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials
• https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4
• https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0
• https://github.com/advisories/GHSA-4vc4-m8qh-g8jm