Authentication Bypass Vulnerability in ruby-saml Library
CVE-2025-66567

9.3CRITICAL

Key Information:

Vendor

Saml-toolkits

Status
Ruby-saml
Vendor
CVE Published:
9 December 2025

What is CVE-2025-66567?

The ruby-saml library, used for SAML authorization, has an authentication bypass issue due to an incomplete fix for a previous vulnerability. This flaw arises from differing XML parsing methods by ReXML and Nokogiri, which can lead to Signature Wrapping attacks. Attackers can exploit this vulnerability in versions of ruby-saml up to and including 1.12.4. It is crucial for users to update to version 1.18.0 or later to mitigate this risk.

Affected Version(s)

ruby-saml < 1.18.0

References

https://github.com/SAML-Toolkits/ruby-saml/security/advis...
x_refsource_CONFIRM
https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdb...
x_refsource_MISC
https://github.com/advisories/GHSA-754f-8gm6-c4r2
x_refsource_MISC

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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