CVE-2026-20920

Win32k Elevation of Privilege Vulnerability

CVE-2026-20920 is fixed in 5 products on 1 platform, first by KB5073455, released January 13, 2026. It is not reported as exploited. Patch Radar priority: High.

High

CVSS

7.8

Important

Exploitation

None reported

Exploitation Unlikely

CISA KEV

Not listed

Not in the Known Exploited Vulnerabilities catalog

EPSS

0.0049

42nd percentile

<p>Use after free in Windows Win32K - ICOMP allows an authorized attacker to elevate privileges locally.</p>

Where it's fixed

Product	Fixed in	Fix	Released
Microsoft
Windows 11 Version 23H2 for ARM64-based Systems	22631.6491	KB5073455	Jan 13, 2026
Windows 11 Version 23H2 for x64-based Systems	22631.6491	KB5073455	Jan 13, 2026
Windows Server 2022	20348.4648	KB5073457	Jan 13, 2026
Windows Server 2022 (Server Core installation)	20348.4648	KB5073457	Jan 13, 2026
Windows Server 2022, 23H2 Edition (Server Core installation)	25398.2092	KB5073450	Jan 13, 2026

Details

Published
January 13, 2026
Weakness
Use After Free
Vendor advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20920

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