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-2021-40450
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 .0158 74.7 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 – —
+ 1 more
TIMELINE
Sep 2 Reserved by microsoft
Oct 13 Published (CNA: microsoft)
Apr 25 Added to CISA KEV, remediation due 2022-05-16
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) |
| April 25, 2022 | KEV ADDED | Added to CISA KEV, remediation due 2022-05-16 |
Affected
Affected products and packages — 11 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 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-40450 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.
