What is CVE-2025-66568?

CVE-2025-66568 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-2025-66568?

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

Vulnerability in Onelogin Ruby-saml

CVE-2025-66568

The ruby-saml library implements the client side of an SAML authorization. Versions up to and including 1.12.4, are vulnerable to authentication bypass through the libxml2 canonicalization process used by Nokogiri for document transformati…

EPSS: 0.002 (12.2th 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 (x_refsource_MISC, Broken Link)

Frequently asked questions

What is CVE-2025-66568?: CVE-2025-66568 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-2025-66568?: Critical severity. CVSS v3 base score is 9.1 out of 10.