ACTIVELY EXPLOITED

CVE-2026-68820: Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability

Facts
VendorMicrosoft
ProductWindows Ancillary Function Driver for WinSock
Actively exploitedYes
Added to CISA KEV11 Aug 2026
CISA federal deadline25 Aug 2026
Weakness (CWE)CWE-416

Required action (CISA's text)

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Description (NVD)

Microsoft Windows Ancillary Function Driver for WinSock contains a use-after-free vulnerability that allows an authorized attacker to elevate privileges locally.

SOURCES

Other Microsoft flaws

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.