CVE-2026-20831
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
A time-of-check time-of-use (TOCTOU) race condition exists in the Windows Ancillary Function Driver for WinSock. This allows an authorized attacker to elevate privileges locally.
Risk Assessment
An authorized user could exploit a timing window to gain elevated privileges, potentially compromising network and system security.
Recommendation
Install the latest Windows security updates.
Other vulnerabilities in Windows Ancillary Function Driver for WinSock
See all- CVE-2026-88149High
A double free vulnerability in the Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2026-83738High
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2026-70245High
A type confusion in the Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2026-70237High
Use after free vulnerability in the Windows Ancillary Function Driver for WinSock. An authorized attacker can elevate privileges locally.
- CVE-2026-70225High
Type confusion (access of resource using incompatible type) in the Windows Ancillary Function Driver for WinSock. An authorized attacker can elevate privileges locally.
- CVE-2026-70205High
Access of resource using incompatible type ('type confusion') in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- CVE-2026-70195Medium
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to disclose information locally.
- CVE-2026-70168High
Use after free in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
- 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.
Original NVD description (English source)
Time-of-check time-of-use (toctou) race condition in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS