What is CVE-2025-66567?

CVE-2025-66567 is a critical-severity vulnerability in Onelogin Ruby-saml, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.1/10. Published 2025-12-09.

How severe is CVE-2025-66567?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Onelogin Ruby-saml

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…

EPSS: 0.004 (32.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Onelogin Ruby-saml
Saml-toolkits Ruby-saml — versions < 1.18.0

Weakness classification (CWE)

CWE-347 — Improper Verification of Cryptographic Signature

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC, Not Applicable)

Frequently asked questions

What is CVE-2025-66567?: CVE-2025-66567 is a critical-severity vulnerability in Onelogin Ruby-saml, classified under Improper Verification of Cryptographic Signature. CVSS score: 9.1/10. Published 2025-12-09.
How severe is CVE-2025-66567?: Critical severity. CVSS v3 base score is 9.1 out of 10.