CVE-2025-66567
Ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
Description
### Summary 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
How to fix CVE-2025-66567
To remediate CVE-2025-66567, upgrade the affected package to a fixed version below.
- —upgrade to 1.18.0 or later
Is CVE-2025-66567 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 1.18.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |