Actively exploited in the wild
Microsoft Windows Ancillary Function Driver for WinSock Heap-Based Buffer Overflow Vulnerability
Microsoft - Windows · Listed in the CISA KEV since 2025-02-11. This indicates confirmed attacks in production environments.
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CVE-2025-21418
HighCVSS 7.8KEVSummary
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability.
Risk Assessment
The risk includes potential privilege escalation by a local attacker, which could lead to full system compromise.
Recommendation
Apply the security updates released by Microsoft for Windows systems.
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-2026-68820HighActively exploited
Use-after-free in Windows Ancillary Function Driver for WinSock. An authorized attacker can elevate privileges locally.
- CVE-2026-20860High
A type confusion vulnerability in the Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- 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)
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability