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CVE-2025-25291VulnerabilityPublished Updated

CVE-2025-25291: ruby-saml · Improper Verification of Cryptographic Signature

Affects ruby-samlSource CVE Database V5

0

Not known to be exploited · 20% EPSS · CVSS 9.3 Critical : upgrade to 1.12.4 as a priority.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 4.0 base score
9.3Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
20.9% chance of exploitation in 30 days – higher than 97% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 1.12.4
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

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 12 Mar 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

What to do

Upgrade ruby-saml to 1.12.4.

Affected software

ProductAffectedFixed in
SAML-Toolkits ruby-samlAffected
  • <1.12.4
Fixed in
  • 1.12.4

AI-suggested

European organizations should immediately upgrade ruby-saml to versions 1.12.4 or 1.18.0 where the vulnerability is patched. Beyond upgrading, organizations should audit their SAML implementations to ensure consistent XML parsing and signature verification processes. Employing XML security libraries that are resistant to signature wrapping attacks or implementing additional validation layers can reduce risk. Monitoring authentication logs for anomalies indicative of signature wrapping or unusual SSO activity is recommended. Organizations should also conduct penetration testing focused on SAML assertion handling to detect potential exploitation paths. Where feasible, consider implementing multi-factor authentication (MFA) to mitigate the impact of authentication bypass. Finally, maintain up-to-date threat intelligence and apply security patches promptly to reduce exposure windows.

Description

ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. An authentication bypass vulnerability was found in ruby-saml prior to versions 1.12.4 and 1.18.0 due to a parser differential. ReXML and Nokogiri parse XML differently; the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. This issue may lead to authentication bypass. Versions 1.12.4 and 1.18.0 fix the issue.

References

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