Critical severityNVD Advisory· Published Dec 9, 2025· Updated Dec 9, 2025
ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
CVE-2025-66567
Description
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
ruby-samlRubyGems | < 1.18.0 | 1.18.0 |
Affected products
2- Range: < 1.18.0
Patches
Vulnerability mechanics
References
6- github.com/advisories/GHSA-754f-8gm6-c4r2ghsax_refsource_MISCADVISORY
- github.com/advisories/GHSA-9v8j-x534-2fx3ghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2025-66567ghsaADVISORY
- github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97ghsax_refsource_MISCWEB
- github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3ghsax_refsource_CONFIRMWEB
- github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-66567.ymlghsaWEB
News mentions
1- The Fragile Lock: Novel Bypasses For SAML AuthenticationPortSwigger Research · Dec 10, 2025