CVE-2025-66567
ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
Description
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.
INFO
Published Date :
Dec. 9, 2025, 4:18 p.m.
Last Modified :
Dec. 10, 2025, 9:27 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | [email protected] | ||||
| CVSS 4.0 | CRITICAL | [email protected] |
Solution
- Update ruby-saml to version 1.18.0.
- Ensure XML parsing is handled securely.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66567.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66567 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66567
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66567 vulnerability anywhere in the article.
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CybersecurityNews
Ruby SAML Library Vulnerability Let Attackers Bypass Authentication
A critical vulnerability has been discovered in the Ruby SAML library that could allow attackers to bypass authentication mechanisms in affected applications completely. The flaw, tracked as CVE-2025- ... Read more
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Daily CyberSecurity
Critical Authentication Bypass Flaws Discovered in Ruby SAML Library (CVE-2025-66567 & CVE-2025-66568)
A pair of critical security vulnerabilities has been disclosed in the Ruby SAML library, a foundational tool used by developers to implement client-side SAML authorization. Both flaws carry a critical ... Read more
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Daily CyberSecurity
CISA KEV Alert: EOL D-Link and Array Networks Command Injection Under Active Attack
The Cybersecurity and Infrastructure Security Agency (CISA) has updated its Known Exploited Vulnerabilities (KEV) Catalog with two distinct but equally dangerous threats: a critical flaw in legacy D-L ... Read more
The following table lists the changes that have been made to the
CVE-2025-66567 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Dec. 10, 2025
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added CPE Configuration OR *cpe:2.3:a:onelogin:ruby-saml:*:*:*:*:*:*:*:* versions up to (excluding) 1.18.0 Added Reference Type GitHub, Inc.: https://github.com/advisories/GHSA-754f-8gm6-c4r2 Types: Not Applicable Added Reference Type GitHub, Inc.: https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3 Types: Vendor Advisory -
New CVE Received by [email protected]
Dec. 09, 2025
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 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 Added CWE CWE-347 Added Reference https://github.com/advisories/GHSA-754f-8gm6-c4r2 Added Reference https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97 Added Reference https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3