CVE-2025-21418

HIGHNVD 7.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2025-02-11), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 7.8 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, ghsa, nvd
Trending — 5 sources updated this weekExploited in the wild
7.8
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS: 2%CVSS: 7.8Exploit: NoneExposed: 0

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

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

CVSS v3
7.8
EG Score
9.0(high)
EG Risk
81(Attend)
EG Risk 81/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability0% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS
72.2%
KEV
⚠ Exploited

Published

February 11, 2025

Last Modified

October 27, 2025

Advisory Details (2)

Auto-updated Jun 3, 2026
⚠️ Active exploitation confirmed. Patch available. Sources: microsoft, cisa.
cisa Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21418
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21418

Vendor Advisories for CVE-2025-21418(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 75× in last 7d / 369× 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.

Showing the most recent 100 of 679 total refreshes for this CVE.

  1. 2026-07-24 14:17 UTCEPSS rescore
  2. 2026-07-23 14:17 UTCEPSS rescore
  3. 2026-07-23 02:50 UTCEG score recompute
  4. 2026-07-22 22:00 UTCEG score recompute
  5. 2026-07-22 22:00 UTCVendor advisory
  6. 2026-07-22 22:00 UTCGHSA enrichment
  7. 2026-07-22 19:40 UTCCISA KEV update
  8. 2026-07-22 17:40 UTCEG score recompute
  9. 2026-07-22 17:40 UTCGHSA enrichment
  10. 2026-07-22 14:07 UTCEPSS rescore
  11. 2026-07-22 14:07 UTCEPSS rescore
  12. 2026-07-22 13:20 UTCVendor advisory
  13. 2026-07-22 13:20 UTCGHSA enrichment
  14. 2026-07-22 09:00 UTCVendor advisory
  15. 2026-07-22 09:00 UTCGHSA enrichment
  16. 2026-07-22 04:41 UTCVendor advisory
  17. 2026-07-22 04:41 UTCGHSA enrichment
  18. 2026-07-22 00:21 UTCVendor advisory
  19. 2026-07-22 00:21 UTCGHSA enrichment
  20. 2026-07-21 20:02 UTCVendor advisory
  21. 2026-07-21 20:01 UTCGHSA enrichment
  22. 2026-07-21 15:39 UTCEG score recompute
  23. 2026-07-21 15:39 UTCVendor advisory
  24. 2026-07-21 15:39 UTCGHSA enrichment
  25. 2026-07-21 15:24 UTCEPSS rescore
Show 75 more
  1. 2026-07-21 14:37 UTCCISA KEV update
  2. 2026-07-21 11:19 UTCVendor advisory
  3. 2026-07-21 11:19 UTCGHSA enrichment
  4. 2026-07-21 06:58 UTCVendor advisory
  5. 2026-07-21 06:58 UTCGHSA enrichment
  6. 2026-07-21 02:39 UTCVendor advisory
  7. 2026-07-21 02:38 UTCGHSA enrichment
  8. 2026-07-20 22:18 UTCVendor advisory
  9. 2026-07-20 22:18 UTCGHSA enrichment
  10. 2026-07-20 17:59 UTCEG score recompute
  11. 2026-07-20 17:59 UTCVendor advisory
  12. 2026-07-20 17:59 UTCGHSA enrichment
  13. 2026-07-20 17:07 UTCEPSS rescore
  14. 2026-07-20 13:40 UTCGHSA enrichment
  15. 2026-07-20 09:21 UTCVendor advisory
  16. 2026-07-20 09:21 UTCGHSA enrichment
  17. 2026-07-20 05:02 UTCVendor advisory
  18. 2026-07-20 05:02 UTCGHSA enrichment
  19. 2026-07-20 00:42 UTCVendor advisory
  20. 2026-07-19 20:23 UTCVendor advisory
  21. 2026-07-19 20:23 UTCGHSA enrichment
  22. 2026-07-19 16:03 UTCEG score recompute
  23. 2026-07-19 16:03 UTCVendor advisory
  24. 2026-07-19 16:03 UTCGHSA enrichment
  25. 2026-07-19 14:30 UTCEPSS rescore
  26. 2026-07-19 14:30 UTCEPSS rescore
  27. 2026-07-19 11:43 UTCVendor advisory
  28. 2026-07-19 11:43 UTCGHSA enrichment
  29. 2026-07-19 07:24 UTCVendor advisory
  30. 2026-07-19 07:24 UTCGHSA enrichment
  31. 2026-07-19 03:04 UTCEG score recompute
  32. 2026-07-19 03:04 UTCVendor advisory
  33. 2026-07-19 03:04 UTCGHSA enrichment
  34. 2026-07-19 02:28 UTCEPSS rescore
  35. 2026-07-19 02:28 UTCEPSS rescore
  36. 2026-07-18 22:44 UTCGHSA enrichment
  37. 2026-07-18 18:24 UTCVendor advisory
  38. 2026-07-18 18:23 UTCGHSA enrichment
  39. 2026-07-18 14:03 UTCEG score recompute
  40. 2026-07-18 14:03 UTCVendor advisory
  41. 2026-07-18 14:03 UTCGHSA enrichment
  42. 2026-07-18 10:03 UTCEPSS rescore
  43. 2026-07-18 09:44 UTCVendor advisory
  44. 2026-07-18 09:44 UTCGHSA enrichment
  45. 2026-07-18 05:25 UTCVendor advisory
  46. 2026-07-18 05:25 UTCGHSA enrichment
  47. 2026-07-18 01:05 UTCVendor advisory
  48. 2026-07-18 01:05 UTCGHSA enrichment
  49. 2026-07-17 20:46 UTCVendor advisory
  50. 2026-07-17 20:46 UTCGHSA enrichment
  51. 2026-07-17 16:27 UTCVendor advisory
  52. 2026-07-17 16:27 UTCGHSA enrichment
  53. 2026-07-17 12:07 UTCVendor advisory
  54. 2026-07-17 12:07 UTCGHSA enrichment
  55. 2026-07-17 07:48 UTCEG score recompute
  56. 2026-07-17 07:48 UTCVendor advisory
  57. 2026-07-17 07:48 UTCGHSA enrichment
  58. 2026-07-17 03:29 UTCVendor advisory
  59. 2026-07-17 03:29 UTCGHSA enrichment
  60. 2026-07-16 23:10 UTCVendor advisory
  61. 2026-07-16 23:10 UTCGHSA enrichment
  62. 2026-07-16 18:51 UTCVendor advisory
  63. 2026-07-16 18:51 UTCGHSA enrichment
  64. 2026-07-16 17:04 UTCCISA KEV update
  65. 2026-07-16 17:02 UTCEPSS rescore
  66. 2026-07-16 14:32 UTCVendor advisory
  67. 2026-07-16 14:31 UTCGHSA enrichment
  68. 2026-07-16 10:12 UTCVendor advisory
  69. 2026-07-16 10:12 UTCGHSA enrichment
  70. 2026-07-16 05:53 UTCVendor advisory
  71. 2026-07-16 05:53 UTCGHSA enrichment
  72. 2026-07-16 01:34 UTCGHSA enrichment
  73. 2026-07-15 21:14 UTCVendor advisory
  74. 2026-07-15 21:14 UTCGHSA enrichment
  75. 2026-07-15 16:57 UTCEPSS rescore

Frequently asked(6)

What is CVE-2025-21418?
CVE-2025-21418 is a high vulnerability published on February 11, 2025. Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
When was CVE-2025-21418 disclosed?
CVE-2025-21418 was first published in the National Vulnerability Database on February 11, 2025, with the most recent update on October 27, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-21418 actively exploited?
Yes. CISA added CVE-2025-21418 to the Known Exploited Vulnerabilities catalog on February 11, 2025, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2025-21418?
CVE-2025-21418 has a CVSS v3 base score of 7.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2025-21418?
CVE-2025-21418 affects Microsoft Windows. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2025-21418?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-21418, 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.

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