Reference page — cumulative record through Wednesday, October 7, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2021-40449

CVE-2021-40449HIGH

Microsoft Windows 10 Version 1809 — Win32k Elevation of Privilege Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  H  H  H    7.8   .7413   99.5   YES

AFFECTED
  Product                                         Versions  Fixed
  Windows 10 Version 1809                         10.0.0 –  —
  Windows Server 2019                             10.0.0 –  —
  Windows Server 2019 (Server Core installation)  10.0.0 –  —
  Windows 10 Version 1909                         10.0.0 –  —
  Windows 10 Version 21H1                         10.0.0 –  —
  Windows Server 2022                             10.0.0 –  —
  Windows 10 Version 2004                         10.0.0 –  —
  Windows Server version 2004                     10.0.0 –  —
  Windows 10 Version 20H2                         10.0.0 –  —
  Windows Server version 20H2                     10.0.0 –  —
  + 17 more

TIMELINE
  Sep 2   Reserved by microsoft
  Oct 13  Published (CNA: microsoft)
  Nov 17  Added to CISA KEV, remediation due 2021-12-01

CWE-416 · CNA: microsoft · CVSS v3.1 · 3 references · KEV due December 1, 2021

Description

Win32k Elevation of Privilege Vulnerability

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
September 2, 2021	Reserved	Reserved by microsoft
October 13, 2021	Published	Published (CNA: microsoft)
November 17, 2021	KEV ADDED	Added to CISA KEV, remediation due 2021-12-01

Affected

Affected products and packages — 27 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Microsoft	Windows 10 Version 1809	—	10.0.0	—
Microsoft	Windows Server 2019	—	10.0.0	—
Microsoft	Windows Server 2019 (Server Core installation)	—	10.0.0	—
Microsoft	Windows 10 Version 1909	—	10.0.0	—
Microsoft	Windows 10 Version 21H1	—	10.0.0	—
Microsoft	Windows Server 2022	—	10.0.0	—
Microsoft	Windows 10 Version 2004	—	10.0.0	—
Microsoft	Windows Server version 2004	—	10.0.0	—
Microsoft	Windows 10 Version 20H2	—	10.0.0	—
Microsoft	Windows Server version 20H2	—	10.0.0	—
Microsoft	Windows 11 version 21H2	—	10.0.0	—
Microsoft	Windows 10 Version 1507	—	10.0.0	—
Microsoft	Windows 10 Version 1607	—	10.0.0	—
Microsoft	Windows Server 2016	—	10.0.0	—
Microsoft	Windows Server 2016 (Server Core installation)	—	10.0.0	—
Microsoft	Windows 7	—	6.1.0	—
Microsoft	Windows 7 Service Pack 1	—	6.1.0	—
Microsoft	Windows 8.1	—	6.3.0	—
Microsoft	Windows Server 2008 Service Pack 2	—	6.0.0	—
Microsoft	Windows Server 2008 Service Pack 2 (Server Core installation)	—	6.0.0	—
Microsoft	Windows Server 2008 Service Pack 2	—	6.0.0	—
Microsoft	Windows Server 2008 R2 Service Pack 1	—	6.1.0	—
Microsoft	Windows Server 2008 R2 Service Pack 1 (Server Core installation)	—	6.0.0	—
Microsoft	Windows Server 2012	—	6.2.0	—
Microsoft	Windows Server 2012 (Server Core installation)	—	6.2.0	—
Microsoft	Windows Server 2012 R2	—	6.3.0	—
Microsoft	Windows Server 2012 R2 (Server Core installation)	—	6.3.0	—

Weaknesses

CWE-416

References (3)

http://packetstormsecurity.com/files/164926/Win32k-NtGdiResetDC-Use-After-Free-Local-Privilege-Escalation.html [x_refsource_MISC]
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-40449 [x_refsource_MISC]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40449 [government-resource]

Authoritative record: CVE-2021-40449 at cve.org

Vendors: microsoft

Weaknesses: CWE-416

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-40449 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, October 7, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.