9.3

CVE-2025-66567: onelogin ruby-saml

CVSS: 9.3v4.0CriticalAnalyzed
AliasesUBUNTU-CVE-2025-66567GHSA-9v8j-x534-2fx3
Published 09-12-2025Last modified 09-12-2025
Open JSON

Vulnerability summary

CVE-2025-66567 is a critical (CVSS 9.3) vulnerability in onelogin ruby-saml. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.8% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.3/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.39%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 0 · Related 1
CVE-2025-25292

Timeline

  1. 09-12-2025
    PublishedVulnerability first disclosed.
  2. 09-12-2025
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

6 scores · 4 sources · 2 versions

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

32%

Versus all other CVEs

30-day change

0.00 pp

From 0.39% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.39%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Onelogin1 product
RubyGems1 product
  • ruby-saml< 1.18.0
Saml-toolkits1 product
Ubuntu1 product
  • ruby-samlAll versions (No fix recorded)

4 vendors · 4 products

References

8 links