CVE-2021-40449

CRITICALNVD 7.89.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2021-11-17), 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
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 74%CVSS: 7.8Exploit: cisa kev · ssvc active · kev ransomware · Metasploit · epss top5pct · epss high · public exploitExposed: 0

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

Win32k 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 PROB
74%
EPSS %ILE
99%
KEV
⚠ Exploited

Published

October 13, 2021

Last Modified

October 30, 2025

Advisory Details (3)

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-2021-40449
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

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

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40449
generic

Packet Storm

http://packetstormsecurity.com/files/164926/Win32k-NtGdiResetDC-Use-After-Free-Local-Privilege-Escalation.html

Weakness Classification(2)

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

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 96× in last 7d / 397× 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 1,476 total refreshes for this CVE.

  1. 2026-09-25 19:35 UTCCISA KEV update
  2. 2026-09-25 19:11 UTCVendor advisory
  3. 2026-09-25 19:11 UTCGHSA enrichment
  4. 2026-09-25 15:05 UTCVendor advisory
  5. 2026-09-25 15:05 UTCGHSA enrichment
  6. 2026-09-25 14:55 UTCCISA KEV update
  7. 2026-09-25 10:58 UTCGHSA enrichment
  8. 2026-09-25 06:51 UTCVendor advisory
  9. 2026-09-25 06:51 UTCGHSA enrichment
  10. 2026-09-25 02:46 UTCVendor advisory
  11. 2026-09-25 02:46 UTCGHSA enrichment
  12. 2026-09-24 22:40 UTCVendor advisory
  13. 2026-09-24 22:40 UTCGHSA enrichment
  14. 2026-09-24 19:31 UTCCISA KEV update
  15. 2026-09-24 18:34 UTCVendor advisory
  16. 2026-09-24 18:34 UTCGHSA enrichment
  17. 2026-09-24 14:29 UTCEG score recompute
  18. 2026-09-24 14:29 UTCVendor advisory
  19. 2026-09-24 14:29 UTCGHSA enrichment
  20. 2026-09-24 14:00 UTCEPSS rescore
  21. 2026-09-24 14:00 UTCEPSS rescore
  22. 2026-09-24 10:23 UTCVendor advisory
  23. 2026-09-24 10:23 UTCGHSA enrichment
  24. 2026-09-24 06:17 UTCVendor advisory
  25. 2026-09-24 06:17 UTCGHSA enrichment
Show 75 more
  1. 2026-09-24 02:11 UTCVendor advisory
  2. 2026-09-24 02:11 UTCGHSA enrichment
  3. 2026-09-23 22:06 UTCVendor advisory
  4. 2026-09-23 22:06 UTCGHSA enrichment
  5. 2026-09-23 18:00 UTCVendor advisory
  6. 2026-09-23 18:00 UTCGHSA enrichment
  7. 2026-09-23 13:54 UTCEG score recompute
  8. 2026-09-23 13:54 UTCVendor advisory
  9. 2026-09-23 13:54 UTCGHSA enrichment
  10. 2026-09-23 13:44 UTCEPSS rescore
  11. 2026-09-23 09:49 UTCVendor advisory
  12. 2026-09-23 09:49 UTCGHSA enrichment
  13. 2026-09-23 05:43 UTCVendor advisory
  14. 2026-09-23 05:43 UTCGHSA enrichment
  15. 2026-09-23 01:38 UTCVendor advisory
  16. 2026-09-23 01:38 UTCGHSA enrichment
  17. 2026-09-22 21:32 UTCVendor advisory
  18. 2026-09-22 21:32 UTCGHSA enrichment
  19. 2026-09-22 19:36 UTCCISA KEV update
  20. 2026-09-22 17:27 UTCEG score recompute
  21. 2026-09-22 17:27 UTCVendor advisory
  22. 2026-09-22 17:27 UTCGHSA enrichment
  23. 2026-09-22 14:44 UTCEPSS rescore
  24. 2026-09-22 13:18 UTCVendor advisory
  25. 2026-09-22 13:18 UTCGHSA enrichment
  26. 2026-09-22 09:13 UTCVendor advisory
  27. 2026-09-22 09:12 UTCGHSA enrichment
  28. 2026-09-22 05:06 UTCVendor advisory
  29. 2026-09-22 05:06 UTCGHSA enrichment
  30. 2026-09-22 01:00 UTCVendor advisory
  31. 2026-09-22 01:00 UTCGHSA enrichment
  32. 2026-09-21 20:54 UTCEG score recompute
  33. 2026-09-21 20:54 UTCVendor advisory
  34. 2026-09-21 20:54 UTCGHSA enrichment
  35. 2026-09-21 20:28 UTCEPSS rescore
  36. 2026-09-21 19:09 UTCCISA KEV update
  37. 2026-09-21 16:48 UTCVendor advisory
  38. 2026-09-21 16:48 UTCGHSA enrichment
  39. 2026-09-21 12:42 UTCVendor advisory
  40. 2026-09-21 12:42 UTCGHSA enrichment
  41. 2026-09-21 08:37 UTCVendor advisory
  42. 2026-09-21 08:36 UTCGHSA enrichment
  43. 2026-09-21 04:28 UTCVendor advisory
  44. 2026-09-21 04:28 UTCGHSA enrichment
  45. 2026-09-21 00:21 UTCVendor advisory
  46. 2026-09-21 00:21 UTCGHSA enrichment
  47. 2026-09-20 20:13 UTCVendor advisory
  48. 2026-09-20 20:13 UTCGHSA enrichment
  49. 2026-09-20 16:07 UTCVendor advisory
  50. 2026-09-20 16:07 UTCGHSA enrichment
  51. 2026-09-20 12:02 UTCVendor advisory
  52. 2026-09-20 12:02 UTCGHSA enrichment
  53. 2026-09-20 07:55 UTCVendor advisory
  54. 2026-09-20 07:55 UTCGHSA enrichment
  55. 2026-09-20 03:49 UTCVendor advisory
  56. 2026-09-20 03:48 UTCGHSA enrichment
  57. 2026-09-19 23:42 UTCVendor advisory
  58. 2026-09-19 23:42 UTCGHSA enrichment
  59. 2026-09-19 19:36 UTCVendor advisory
  60. 2026-09-19 19:36 UTCGHSA enrichment
  61. 2026-09-19 15:30 UTCVendor advisory
  62. 2026-09-19 15:30 UTCGHSA enrichment
  63. 2026-09-19 11:25 UTCVendor advisory
  64. 2026-09-19 11:24 UTCGHSA enrichment
  65. 2026-09-19 07:18 UTCVendor advisory
  66. 2026-09-19 07:18 UTCGHSA enrichment
  67. 2026-09-19 03:12 UTCVendor advisory
  68. 2026-09-19 03:12 UTCGHSA enrichment
  69. 2026-09-18 23:07 UTCEG score recompute
  70. 2026-09-18 23:07 UTCVendor advisory
  71. 2026-09-18 23:07 UTCGHSA enrichment
  72. 2026-09-18 19:23 UTCEPSS rescore
  73. 2026-09-18 19:20 UTCCISA KEV update
  74. 2026-09-18 19:01 UTCVendor advisory
  75. 2026-09-18 19:01 UTCGHSA enrichment

Publicly available exploits

(7 references)

Working exploit code is in the public domain (1 Metasploit module) (6 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCSamuelTulach/voidmap
    First seen Mar 4, 2022

    Using CVE-2021-40449 to manual map kernel mode driver

    Open source ↗
  • GitHub PoCBL0odz/CVE-2021-40449-NtGdiResetDC-UAF
    First seen Feb 20, 2022
    Open source ↗
  • GitHub PoCKristal-g/CVE-2021-40449_poc
    First seen Nov 7, 2021

    Exploit for CVE-2021-40449

    Open source ↗
  • GitHub PoChakivvi/CVE-2021-40449
    First seen Oct 25, 2021

    LPE exploit for a UAF in Windows (CVE-2021-40449).

    Open source ↗
  • GitHub PoCKaLendsi/CVE-2021-40449-Exploit
    First seen Oct 20, 2021

    windows 10 14393 LPE

    Open source ↗
  • GitHub PoCly4k/CallbackHell
    First seen Oct 16, 2021

    Exploit for CVE-2021-40449 - Win32k Elevation of Privilege Vulnerability (LPE)

    Open source ↗
  • Metasploitexploit/windows/local/cve_2021_40449✓ verified
    First seen Oct 12, 2021

    Win32k NtGdiResetDC Use After Free Local Privilege Elevation

    Open source ↗

Related CVEs(same CWE)

Frequently asked(6)

What is CVE-2021-40449?
CVE-2021-40449 is a critical vulnerability published on October 13, 2021. Win32k Elevation of Privilege Vulnerability
When was CVE-2021-40449 disclosed?
CVE-2021-40449 was first published in the National Vulnerability Database on October 13, 2021, with the most recent update on October 30, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-40449 actively exploited?
Yes. CISA added CVE-2021-40449 to the Known Exploited Vulnerabilities catalog on November 17, 2021, affecting Microsoft Windows. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2021-40449?
CVE-2021-40449 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-2021-40449?
CVE-2021-40449 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-2021-40449?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-40449, 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

Explore the affected products and dependency analysis for CVE-2021-40449

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