9.3

CVE-2025-66568: onelogin ruby-saml

CVSS: 9.3v4.0CriticalAnalyzed
AliasesUBUNTU-CVE-2025-66568GHSA-x4h9-gwv3-r4m4
Published 09-12-2025Last modified 09-12-2025
Open JSON

Vulnerability summary

CVE-2025-66568 is a critical (CVSS 9.3) vulnerability in onelogin ruby-saml. EPSS estimates a 0.24% chance of exploitation in the next 30 days, higher than 13.5% 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
0.24%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

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

Description

The ruby-saml library implements the client side of an SAML authorization. Versions up to and including 1.12.4, are vulnerable to authentication bypass through the libxml2 canonicalization process used by Nokogiri for document transformation, which allows an attacker to execute a Signature Wrapping attack. When libxml2’s canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded. This issue is fixed in version 1.18.0.

CVSS metrics

6 scores · 4 sources · 2 versions

EPSS trend

Probability

0.24%

Chance of exploitation in the next 30 days

Percentile

14%

Versus all other CVEs

30-day change

0.00 pp

From 0.23% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.24%

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

7 links