CVE-2025-66568

CRITICAL EPSS 10.9%
Published Dec 9, 20256mo ago · Modified Jun 17, 20262w ago
9.3 CVSS 4.0
Critical
Find Similar
Published Dec 9, 2025 6mo ago
Last Modified Jun 17, 2026 2w ago

Description

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 transformation, which allows an attacker to execute a Signature Wrapping attack. When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded. This issue is fixed in version 1.18.0.

CVSS Details

Base Score
9.3
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
10.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-347

Affected Products 1

VendorProductVersionRange
oneloginruby-saml* <1.18.0

References 2

  • github.com https://github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349a
    Broken Link
  • github.com https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-x4h9-gwv3-r4m4
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.