CVE-2025-66568
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-12-09

Last updated on: 2025-12-10

Assigner: GitHub, Inc.

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.
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Meta Information
Published
2025-12-09
Last Modified
2025-12-10
Generated
2026-06-16
AI Q&A
2025-12-09
EPSS Evaluated
2026-06-15
NVD
CVE-2025-66568
Affected Vendors & Products
Showing 3 associated CPEs
Vendor Product Version / Range
ruby-saml ruby-saml 1.12.4
ruby-saml ruby-saml 1.18.0
onelogin ruby-saml to 1.18.0 (inc)
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-347 The product does not verify, or incorrectly verifies, the cryptographic signature for data.
Attack-Flow Graph
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Executive Summary

This vulnerability exists in the ruby-saml library versions up to 1.12.4, where an attacker can bypass authentication by exploiting the libxml2 canonicalization process used by Nokogiri. When libxml2 processes invalid XML input, it may return an empty string instead of a canonicalized node. ruby-saml then incorrectly computes the DigestValue over this empty string, allowing a Signature Wrapping attack that can bypass authentication.

Impact Analysis

This vulnerability can allow an attacker to bypass authentication mechanisms in applications using vulnerable versions of ruby-saml, potentially granting unauthorized access to protected resources or systems.

Mitigation Strategies

Upgrade the ruby-saml library to version 1.18.0 or later, as this version contains the fix for the authentication bypass vulnerability caused by the libxml2 canonicalization process.

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