CyberICT

CVE-2026-21238

Microsoft · Published February 10, 2026

CVSS v3.1

HIGH
Patch availableGet patch

Description

Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability. Improper access control in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Affected Products

  • Windows 11 Version 26H1 for ARM64-based Systems
  • Windows 11 version 26H1 for x64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems

CVSS Vector

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