CVE-2025-66567

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.

CVSS 4.0

9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

9.1CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 35% of CVEs (scores of 2026-10-25)

CWE

CWE-347

Published

2025-12-09

Modified

2026-10-14

Record from

the NVD, synced 2026-10-19

Affected

• onelogin:ruby-saml

Packages (OSV)

References

• https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
• https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
• https://github.com/advisories/GHSA-754f-8gm6-c4r2

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