CVE-2025-66567 json
ruby-saml has a SAML authentication bypass due to namespace handling (parser differential)
published 2025-12-08 11 mo ago modified 2026-10-14 25 d ago also EUVD-2025-201812 , GHSA-9v8j-x534-2fx3
- cvss
- 9.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 36%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- rubygems ruby-saml 1.18.0
- onelogin ruby-saml 1.18.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 10 mo ago
Exploit prediction
0.42% chance of exploitation in the next 30 days, higher than 36% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | 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 |
| CNA | 4.0 | 9.3 | 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/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 |
| NVD | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| rubygems | ruby-saml | <1.18.0 |
1.18.0 |
Affected products
- SAML-Toolkits ruby-saml
Classification
- Weakness
-
- CWE-347 Improper Verification of Cryptographic Signature
References
-
github.com
/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97
web, patch
-
github.com
/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
web, vendor-advisory
-
github.com
/advisories/GHSA-754f-8gm6-c4r2
advisory, not-applicable
-
nvd.nist.gov
/vuln/detail/CVE-2025-66567
advisory
-
github.com
/SAML-Toolkits/ruby-saml
package
-
github.com
/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-66567.yml
web
Sources
- CVE List CVE-2025-66567
- GitHub Advisory GHSA-9v8j-x534-2fx3
- NVD CVE-2025-66567
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.