Ruby SAML vulnerable to SAML authentication bypass due to namespace handling (parser differential)
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. An authentication bypass vulnerability was found in ruby-saml prior to versions 1.12.4 and 1.18.0 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. This issue may lead to authentication bypass. Versions 1.12.4 and 1.18.0 contain a patch for the issue.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2025-25292US | critical9.8 | — | ||
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. An authentication bypass vulnerability was found in ruby-saml prior to versions 1.12.4 a… | ||||
references
External citations — patches, advisories, analysis.
- https://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-releasedFIX
- https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentialsADVISORY
- https://github.com/SAML-Toolkits/ruby-saml/commit/e76c5b36bac40aedbf1ba7ffaaf495be63328cd9FIX
- https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97FIX
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4ARTICLE
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0ARTICLE
- https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-754f-8gm6-c4r2ADVISORY
- https://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xvADVISORY
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