CVE-2025-66567

moderate-risk
Published 2025-12-09

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.

Do I need to act?

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0.05% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.1/10 Critical
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

36
/ 100
moderate-risk
Severity 31/34 · Critical
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal