CVE-2025-66567

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

Published Dec 9, 2025 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-9v8j-x534-2fx3 Ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
History
Type Values Removed Values Added
First Time appeared Onelogin
Onelogin ruby-saml
CPEs cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:*
Vendors & Products Onelogin
Onelogin ruby-saml
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Saml-toolkits
Saml-toolkits ruby-saml
Vendors & Products Saml-toolkits
Saml-toolkits ruby-saml
Type Values Removed Values Added
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.
Title ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
Weaknesses CWE-347
References
Metrics cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Dec 9, 2025, 4:02 PM
Reserved
Dec 4, 2025, 4:17 PM
Status
Analyzed
Published
Dec 9, 2025, 4:18 PM
Modified
Oct 14, 2026, 9:10 PM