CVE-2009-3677

NONECVSS 0.0Elevated
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 22%CVSS: —Exploit: NoneExposed: 0

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

The Internet Authentication Service (IAS) in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold and SP1, and Server 2008 Gold does not properly verify the credentials in an MS-CHAP v2 Protected Extensible Authentication Protocol (PEAP) authentication request, which allows remote attackers to access network resources via a malformed request, aka "MS-CHAP Authentication Bypass Vulnerability."

CVSS v3
—
EG Score
0.0(none)
EPSS
97.3%
KEV
Not listed

Published

December 9, 2009

Last Modified

April 23, 2026

References (8)

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 34× 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. 2026-07-06 16:23 UTCEPSS rescore
  2. 2026-07-05 02:26 UTCEPSS rescore
  3. 2026-07-05 02:26 UTCEPSS rescore
  4. 2026-07-04 06:27 UTCEPSS rescore
  5. 2026-07-01 15:02 UTCEPSS rescore
  6. 2026-06-29 14:02 UTCEPSS rescore
  7. 2026-06-29 14:02 UTCEPSS rescore
  8. 2026-06-28 14:03 UTCEPSS rescore
  9. 2026-06-28 04:52 UTCEPSS rescore
  10. 2026-06-28 04:52 UTCEPSS rescore
  11. 2026-06-27 03:05 UTCEPSS rescore
  12. 2026-06-25 13:46 UTCEPSS rescore
  13. 2026-06-25 13:46 UTCEPSS rescore
  14. 2026-06-24 14:02 UTCEPSS rescore
  15. 2026-06-24 14:02 UTCEPSS rescore
  16. 2026-06-23 21:29 UTCEPSS rescore
  17. 2026-06-23 21:29 UTCEPSS rescore
  18. 2026-06-22 14:22 UTCEPSS rescore
  19. 2026-06-22 14:22 UTCEPSS rescore
  20. 2026-06-21 01:56 UTCEPSS rescore
  21. 2026-06-21 01:56 UTCEPSS rescore
  22. 2026-06-18 17:49 UTCEPSS rescore
  23. 2026-06-18 17:49 UTCEPSS rescore
  24. 2026-06-17 17:49 UTCEPSS rescore
  25. 2026-06-17 17:49 UTCEPSS rescore
Show 41 more
  1. 2026-06-16 17:49 UTCEPSS rescore
  2. 2026-06-16 17:49 UTCEPSS rescore
  3. 2026-06-15 17:44 UTCEPSS rescore
  4. 2026-06-14 23:14 UTCEPSS rescore
  5. 2026-06-14 23:14 UTCEPSS rescore
  6. 2026-06-12 23:08 UTCEPSS rescore
  7. 2026-06-12 23:08 UTCEPSS rescore
  8. 2026-06-10 22:14 UTCEPSS rescore
  9. 2026-06-10 13:17 UTCEPSS rescore
  10. 2026-06-07 15:22 UTCEPSS rescore
  11. 2026-06-07 15:22 UTCEPSS rescore
  12. 2026-06-06 13:44 UTCEPSS rescore
  13. 2026-06-06 13:44 UTCEPSS rescore
  14. 2026-06-06 13:44 UTCEPSS rescore
  15. 2026-06-05 22:44 UTCEPSS rescore
  16. 2026-06-05 22:44 UTCEPSS rescore
  17. 2026-06-05 06:07 UTCEPSS rescore
  18. 2026-06-02 20:10 UTCEPSS rescore
  19. 2026-06-02 20:10 UTCEPSS rescore
  20. 2026-06-01 13:49 UTCEPSS rescore
  21. 2026-06-01 13:49 UTCEPSS rescore
  22. 2026-05-31 22:28 UTCEPSS rescore
  23. 2026-05-31 22:28 UTCEPSS rescore
  24. 2026-05-31 00:13 UTCEPSS rescore
  25. 2026-05-31 00:13 UTCEPSS rescore
  26. 2026-05-30 14:23 UTCEG score recompute
  27. 2026-05-30 14:23 UTCGHSA enrichment
  28. 2026-05-28 13:42 UTCEPSS rescore
  29. 2026-05-28 13:42 UTCEPSS rescore
  30. 2026-05-28 13:42 UTCEPSS rescore
  31. 2026-05-27 13:38 UTCEPSS rescore
  32. 2026-05-27 13:38 UTCEPSS rescore
  33. 2026-05-26 13:41 UTCEPSS rescore
  34. 2026-05-26 13:41 UTCEPSS rescore
  35. 2026-05-26 07:16 UTCEPSS rescore
  36. 2026-05-26 07:16 UTCEPSS rescore
  37. 2026-05-22 21:15 UTCEPSS rescore
  38. 2026-05-22 21:15 UTCEPSS rescore
  39. 2026-05-20 22:37 UTCEPSS rescore
  40. 2026-05-20 22:37 UTCEPSS rescore
  41. 2026-05-18 21:29 UTCEPSS rescore

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Frequently asked(4)

What is CVE-2009-3677?
CVE-2009-3677 is a none vulnerability published on December 9, 2009. The Internet Authentication Service (IAS) in Microsoft Windows 2000 SP4, XP SP2 and SP3, Server 2003 SP2, Vista Gold and SP1, and Server 2008 Gold does not properly verify the credentials in an MS-CHAP v2 Protected Extensible Authentication Protocol (PEAP) authentication request, which allows…
When was CVE-2009-3677 disclosed?
CVE-2009-3677 was first published in the National Vulnerability Database on December 9, 2009, with the most recent update on April 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2009-3677 actively exploited?
CVE-2009-3677 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 97.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2009-3677?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2009-3677, 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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