Microsoft Windows Ancillary Function Driver for WinSock Privilege Escalation Vulnerability

A use-after-free vulnerability has been identified in the Windows Ancillary Function Driver for WinSock. This vulnerability allows an authorized attacker to locally elevate privileges. The issue arises from improper handling of memory, creating a race condition that could be exploited to gain SYSTEM privileges.

Impact

Exploitation of this vulnerability could lead to unauthorized privilege escalation, allowing an attacker to gain SYSTEM privileges.

Remediation

Users can apply the security update for this vulnerability, which is available as part of the June 2026 Monthly Rollup. Instructions for downloading this update can be found in the Microsoft Update Catalog.