CVE-2025-66568: ruby-saml Libxml2 Canonicalization errors can bypass Digest/Signature validation
SAML-Toolkits · ruby-saml
Affected: SAML-Toolkits ruby-saml · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 18% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- SAML-Toolkits · ruby-saml< 1.18.0
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- SAML-Toolkits
- Published
- December 2025
CoverageNo articles yet
No CyberSIXT article names CVE-2025-66568 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.