Summary
Ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0.
Impact
That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-66567? CVE-2025-66567 is a critical-severity security vulnerability in ruby-saml (rubygems), affecting versions < 1.18.0. It is fixed in 1.18.0.
- Which versions of ruby-saml are affected by CVE-2025-66567? ruby-saml (rubygems) versions < 1.18.0 is affected.
- Is there a fix for CVE-2025-66567? Yes. CVE-2025-66567 is fixed in 1.18.0. Upgrade to this version or later.
- Is CVE-2025-66567 exploitable, and should I be worried? Whether CVE-2025-66567 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-66567 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-66567? Upgrade
ruby-samlto 1.18.0 or later.