CVE-2025-66567
EPSS 0.05%Ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
Published: 12/8/2025Modified: 2/4/2026
Also known as:GHSA-9v8j-x534-2fx3
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
Affected packages (1)
- RubyGems/ruby-samlfrom 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 |
References (6)
- ADVISORYhttps://github.com/advisories/GHSA-754f-8gm6-c4r2
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2025-66567
- PATCHhttps://github.com/SAML-Toolkits/ruby-saml
- WEBhttps://github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-66567.yml
- WEBhttps://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
- WEBhttps://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3