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 fix the issue.
CVE-2025-25291
CRITICALNVD 9.8
9.8
- CVSS v3
- 9.8
- EG Score
- —
- EPSS
- —
- KEV
- Not listed
Published
March 12, 2025
Last Modified
November 3, 2025
References (13)
- security-advisories@githubhttps://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released
- security-advisories@githubhttps://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials
- security-advisories@githubhttps://github.com/SAML-Toolkits/ruby-saml/commit/e76c5b36bac40aedbf1ba7ffaaf495be63328cd9
- security-advisories@githubhttps://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
- security-advisories@githubhttps://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4
- security-advisories@githubhttps://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0
- security-advisories@githubhttps://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-4vc4-m8qh-g8jm
- security-advisories@githubhttps://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv
- security-advisories@githubhttps://portswigger.net/research/saml-roulette-the-hacker-always-wins
- security-advisories@githubhttps://securitylab.github.com/advisories/GHSL-2024-329_GHSL-2024-330_ruby-saml
- af854a3a-2127-422b-91ae-364da2661108https://lists.debian.org/debian-lts-announce/2025/04/msg00011.html
- af854a3a-2127-422b-91ae-364da2661108https://news.ycombinator.com/item?id=43374519
- af854a3a-2127-422b-91ae-364da2661108https://security.netapp.com/advisory/ntap-20250314-0010/
Vendor Advisories for CVE-2025-25291(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Frequently asked(4)
What is CVE-2025-25291?
CVE-2025-25291 is a critical vulnerability published on March 12, 2025. 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…
When was CVE-2025-25291 disclosed?
CVE-2025-25291 was first published in the National Vulnerability Database on March 12, 2025, with the most recent update on November 3, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2025-25291?
CVE-2025-25291 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2025-25291?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-25291, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
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