CVE-2026-20810

HIGH

Windows Ancillary Function Driver - Privilege Escalation

Title source: llm

Free of memory not on the heap in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Core 1

Core References

Vendor Advisory vendor-advisory patch

CVSS v3 7.8

EPSS 0.0005

EPSS Percentile 15.7%

Attack Vector LOCAL

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

CWE

CWE-590

Status published

Products (9)

Microsoft/Windows 10 Version 1809 10.0.17763.0 - 10.0.17763.8276

Microsoft/Windows 10 Version 21H2 10.0.19044.0 - 10.0.19044.6809

Microsoft/Windows 10 Version 22H2 10.0.19045.0 - 10.0.19045.6809

Microsoft/Windows Server 2019 10.0.17763.0 - 10.0.17763.8276

Microsoft/Windows Server 2019 (Server Core installation) 10.0.17763.0 - 10.0.17763.8276

microsoft/windows_10_1809 < 10.0.17763.8276 (2 CPE variants)

microsoft/windows_10_21h2 < 10.0.19044.6809

microsoft/windows_10_22h2 < 10.0.19045.6809

microsoft/windows_server_2019 < 10.0.17763.8276

Published Jan 13, 2026

Tracked Since Feb 18, 2026