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CVE-2025-66568

ruby-saml Libxml2 Canonicalization errors can bypass Digest/Signature validation

Published: Dec 9, 2025Updated: Dec 10, 2025 Sources: CVE List NVD GHSACWE-347
9.1CRITICAL
NVD MITRE
EPSS Score
0.2%
Top 85.2%
CISA KEV
Not in KEV
Exploits
1 Known
Remediation
Patch Available
Self-Check
OpenVAS

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:NAvailability
None
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Weaknesses

CWE-347

Affected Products

onelogin
commercial·USaka onelogin saml sso, onelogin saml
ruby-samlSaaS
Security Products / identity-access-mgmt
SAML-Toolkits
oss-projectaka ruby-saml, saml-toolkits ruby-saml
ruby-samlLibrary
OSS Libraries / generic-library
RubyGems
package-ecosystem
ruby-saml
OSS Libraries

Exploitability

1 exploit source identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available
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Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

1 technique
Collection
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References

https://github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349a
github.com
https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-x4h9-gwv3-r4m4
github.com
https://nvd.nist.gov/vuln/detail/CVE-2025-66568
nvd.nist.gov
and 2 more references View all →

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