Actively exploited in the wild
Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability
Microsoft - Windows Ancillary Function Driver for WinSock · Listed in the CISA KEV since 2026-08-11. This indicates confirmed attacks in production environments.
Required action: 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.
CVE-2026-68820
HighCVSS 7.0KEVExploitation Probability (EPSS)
Low risk26th percentile - higher than 26% of all known CVEs
Summary
Use-after-free in Windows Ancillary Function Driver for WinSock. An authorized attacker can elevate privileges locally.
Risk Assessment
Privilege escalation could allow an attacker to gain full control of the system, posing a serious security threat.
Recommendation
Install the latest Windows updates and monitor the system for unusual activity.
Other vulnerabilities in Windows Ancillary Function Driver for WinSock
See all- CVE-2026-34344High
The Windows Ancillary Function Driver for WinSock has a vulnerability related to resource access using an incompatible type ('type confusion'), allowing an authorized attacker to elevate privileges locally.
- CVE-2026-20810High
A vulnerability in the Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally. The issue involves freeing memory not on the heap.
- CVE-2026-20860High
A type confusion vulnerability in the Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2025-21418HighActively exploited
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability.
- CVE-2024-38193HighActively exploited
A vulnerability in the Windows Ancillary Function Driver for WinSock allows for elevation of privilege on Windows systems. The NVD description does not provide technical details or required user interaction.
- CVE-2026-70342High
Use after free in Windows Ancillary Function Driver for WinSock allows an unauthorized attacker to elevate privileges over a network.
- CVE-2026-50349High
A race condition in the Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2026-70307High
A use-after-free vulnerability in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2026-61348High
A use-after-free vulnerability in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2026-57093High
A use-after-free vulnerability in the Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Original NVD description (English source)
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS