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TI-2025-40978 Aliases CVE-2025-66567GHSA-9v8j-x534-2fx3

ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)

Priority MEDIUM 48CWE-347Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-347.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00417 36th percentileScored 2026-11-07
Fix Fixed ruby-saml (SAML-Toolkits): 1.18.0ruby-saml (RubyGems): 1.18.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
SAML-Toolkitsruby-samlbefore 1.18.01.18.0Patch availableCNA
—ruby-saml (RubyGems)before 1.18.01.18.0Patch availableGHSA-9v8j-x534-2fx3
  • ruby-saml VendorSAML-Toolkits Affected before 1.18.0 Fixed in 1.18.0 Patch available CNA
  • ruby-saml (RubyGems) Vendor— Affected before 1.18.0 Fixed in 1.18.0 Patch available GHSA-9v8j-x534-2fx3

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:*before 1.18.0VulnerableSAML-Toolkits
  • cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:* Versions before 1.18.0 Vulnerable ·SAML-Toolkits

Remediation

  • Fix · CNA ruby-saml (SAML-Toolkits) Fixed in 1.18.0
  • Fix · GHSA-9v8j-x534-2fx3 ruby-saml (RubyGems) Fixed in 1.18.0 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-66567
  2. 2026-10-03 Alias added: GHSA-9v8j-x534-2fx3

References

Patch 1

Advisory 3

Other 2

  • TI-2025-18946 Ruby SAML vulnerable to SAML authentication bypass due to namespace handling (parser differential) CVSS 4.0CRITICAL 9.3
  • TI-2024-30458 The Ruby SAML library vulnerable to a SAML authentication bypass via Incorrect XPath selector CVSS 3.1CRITICAL 10.0
  • TI-2025-18945 ruby-saml vulnerable to SAML authentication bypass due to DOCTYPE handling (parser differential) CVSS 4.0CRITICAL 9.3
  • TI-2015-08083 xml_security.rb in the ruby-saml gem before 1.0.0 for Ruby allows XPath injection and… CVSS 3.1CRITICAL 9.8
  • TI-2025-40979 ruby-saml Libxml2 Canonicalization errors can bypass Digest/Signature validation CVSS 4.0CRITICAL 9.3
  • TI-2017-08453 Multiple SAML libraries may allow authentication bypass via incorrect XML canonicalization and DOM traversal CVSS 3.0CRITICAL 9.8
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences