CVE-2025-66567

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 84% 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 is for implementing the client side of a SAML authorization. ruby-saml versions up to and including 1.12.4 contain an authentication bypass vulnerability due to an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, generating entirely different document structures from the same input. This allows an attacker to execute a Signature Wrapping attack. This issue is fixed in version 1.18.0.

CVSS v3
9.1
EG Score
9.1(medium)
EPSS
31.5%
KEV
Not listed

Published

December 9, 2025

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Jul 19, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Ruby SAML allows a SAML authentication bypass due to namespace handling (parser differential) · CVE-2025-25292 · GitHub Advisory Database · GitHub

https://github.com/advisories/GHSA-754f-8gm6-c4r2
github Patch Available

SAML authentication bypass due to namespace handling (parser differential) · Advisory · SAML-Toolkits/ruby-saml · GitHub

https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3
github_commit Patch Available

commit e9c1cdbd0f9a (SAML-Toolkits/ruby-saml)

Patch available: SAML-Toolkits/ruby-saml v1.18.0 (contains commit e9c1cdbd0f9a)

https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2025-66567?
CVE-2025-66567 is a critical vulnerability published on December 9, 2025. The ruby-saml library is for implementing the client side of a SAML authorization. ruby-saml versions up to and including 1.12.4 contain an authentication bypass vulnerability due to an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, generating entirely different…
When was CVE-2025-66567 disclosed?
CVE-2025-66567 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-2025-66567 actively exploited?
CVE-2025-66567 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 31.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2025-66567?
CVE-2025-66567 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2025-66567?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-66567, 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

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