CVE-2025-66568

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.0%, top 85% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
9.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.1Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
9.1
EG Score
9.1(medium)
EPSS
11.5%
KEV
Not listed

Published

December 9, 2025

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Jul 20, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Libxml2 Canonicalization error can bypass Digest/Signature validation · Advisory · SAML-Toolkits/ruby-saml · GitHub

https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-x4h9-gwv3-r4m4
github_commit Patch Available

commit acac9e9cc0b9 (SAML-Toolkits/ruby-saml)

Patch available: SAML-Toolkits/ruby-saml v1.18.0 (contains commit acac9e9cc0b9)

https://github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349a

Affected Packages

(1 across 1 ecosystem)
RubyGems(1)
PackageVulnerable rangeFixed inDependents
ruby-saml0.0.5 ... 1.9.0 (87 versions)1.18.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 43× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:30 UTCEPSS rescore
  5. 2026-07-19 14:30 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-16 17:02 UTCEPSS rescore
  9. 2026-07-15 16:57 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 01:59 UTCEPSS rescore
  12. 2026-07-15 01:59 UTCEPSS rescore
  13. 2026-07-13 22:29 UTCEPSS rescore
  14. 2026-07-13 06:12 UTCEPSS rescore
  15. 2026-07-12 05:46 UTCEPSS rescore
  16. 2026-07-11 08:27 UTCEPSS rescore
  17. 2026-07-09 19:09 UTCEPSS rescore
  18. 2026-07-08 15:15 UTCEPSS rescore
  19. 2026-07-07 13:46 UTCEPSS rescore
  20. 2026-07-06 16:27 UTCEPSS rescore
  21. 2026-07-06 16:27 UTCEPSS rescore
  22. 2026-07-06 08:11 UTCOSV refresh
  23. 2026-07-06 02:23 UTCEPSS rescore
  24. 2026-07-06 02:23 UTCEPSS rescore
  25. 2026-07-05 02:30 UTCEPSS rescore
Show 62 more
  1. 2026-07-05 02:30 UTCEPSS rescore
  2. 2026-07-04 06:31 UTCEPSS rescore
  3. 2026-07-04 06:30 UTCEPSS rescore
  4. 2026-07-01 15:06 UTCEPSS rescore
  5. 2026-07-01 15:06 UTCEPSS rescore
  6. 2026-06-30 23:22 UTCEPSS rescore
  7. 2026-06-29 14:06 UTCEPSS rescore
  8. 2026-06-29 14:06 UTCEPSS rescore
  9. 2026-06-28 14:07 UTCEPSS rescore
  10. 2026-06-28 14:07 UTCEPSS rescore
  11. 2026-06-28 04:56 UTCEPSS rescore
  12. 2026-06-28 04:55 UTCEPSS rescore
  13. 2026-06-27 03:08 UTCEPSS rescore
  14. 2026-06-25 13:49 UTCEPSS rescore
  15. 2026-06-24 14:04 UTCEPSS rescore
  16. 2026-06-24 14:04 UTCEPSS rescore
  17. 2026-06-23 21:32 UTCEPSS rescore
  18. 2026-06-23 21:32 UTCEPSS rescore
  19. 2026-06-22 14:25 UTCEPSS rescore
  20. 2026-06-21 14:56 UTCEPSS rescore
  21. 2026-06-21 14:56 UTCEPSS rescore
  22. 2026-06-21 01:59 UTCEPSS rescore
  23. 2026-06-21 01:59 UTCEPSS rescore
  24. 2026-06-19 19:25 UTCEPSS rescore
  25. 2026-06-19 19:25 UTCEPSS rescore
  26. 2026-06-18 17:52 UTCEPSS rescore
  27. 2026-06-18 17:52 UTCEPSS rescore
  28. 2026-06-17 20:13 UTCOSV refresh
  29. 2026-06-17 17:52 UTCEPSS rescore
  30. 2026-06-16 17:52 UTCEPSS rescore
  31. 2026-06-15 17:48 UTCEPSS rescore
  32. 2026-06-15 17:48 UTCEPSS rescore
  33. 2026-06-14 23:18 UTCEPSS rescore
  34. 2026-06-13 23:00 UTCEPSS rescore
  35. 2026-06-13 23:00 UTCEPSS rescore
  36. 2026-06-12 23:11 UTCEPSS rescore
  37. 2026-06-11 14:00 UTCEPSS rescore
  38. 2026-06-10 22:18 UTCEPSS rescore
  39. 2026-06-10 22:18 UTCEPSS rescore
  40. 2026-06-10 13:22 UTCEPSS rescore
  41. 2026-06-08 14:17 UTCEPSS rescore
  42. 2026-06-08 14:16 UTCEPSS rescore
  43. 2026-06-07 15:24 UTCEPSS rescore
  44. 2026-06-07 15:24 UTCEPSS rescore
  45. 2026-06-06 13:47 UTCEPSS rescore
  46. 2026-06-06 13:47 UTCEPSS rescore
  47. 2026-06-05 22:46 UTCEPSS rescore
  48. 2026-06-05 22:46 UTCEPSS rescore
  49. 2026-06-05 06:10 UTCEPSS rescore
  50. 2026-06-05 06:10 UTCEPSS rescore
  51. 2026-06-04 13:12 UTCEPSS rescore
  52. 2026-06-04 13:12 UTCEPSS rescore
  53. 2026-06-02 20:13 UTCEPSS rescore
  54. 2026-06-02 20:12 UTCEPSS rescore
  55. 2026-06-01 13:51 UTCEPSS rescore
  56. 2026-06-01 13:51 UTCEPSS rescore
  57. 2026-05-31 22:30 UTCEPSS rescore
  58. 2026-05-31 22:30 UTCEPSS rescore
  59. 2026-05-31 00:16 UTCEPSS rescore
  60. 2026-05-31 00:16 UTCEPSS rescore
  61. 2026-05-29 18:08 UTCEG score recompute
  62. 2026-05-29 13:44 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2025-66568?
CVE-2025-66568 is a critical vulnerability published on December 9, 2025. 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…
When was CVE-2025-66568 disclosed?
CVE-2025-66568 was first published in the National Vulnerability Database on December 9, 2025, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-66568 actively exploited?
CVE-2025-66568 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 11.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-66568?
CVE-2025-66568 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2025-66568?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-66568, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2025-66568

Explore →

Is Your Infrastructure Affected by CVE-2025-66568?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs