CVE-2025-32709: Microsoft Windows Ancillary Function Driver for WinSock Use-After-Free Vulnerability

High severity, CVSS 7.8. Actively exploited: in CISA KEV since 2025-05-13. EPSS: 1.8% chance of exploitation in the next 30 days.

Null pointer dereference in Windows Ancillary Function Driver for WinSock allows an authorized attacker to elevate privileges locally.

Affected products

• Microsoft Windows 10 1507: before 10.0.10240.21014 (fixed in 10.0.10240.21014)
• Microsoft Windows 10 1607: before 10.0.14393.8066 (fixed in 10.0.14393.8066)
• Microsoft Windows 10 1809: before 10.0.17763.7314 (fixed in 10.0.17763.7314)
• Microsoft Windows 10 21h2: before 10.0.19044.5854 (fixed in 10.0.19044.5854)
• Microsoft Windows 10 22h2: before 10.0.19045.5854 (fixed in 10.0.19045.5854)
• Microsoft Windows 11 22h2: before 10.0.22621.5335 (fixed in 10.0.22621.5335)
• Microsoft Windows 11 23h2: before 10.0.22631.5335 (fixed in 10.0.22631.5335)
• Microsoft Windows 11 24h2: before 10.0.26100.3981 (fixed in 10.0.26100.3981)
• Microsoft Windows Server 2008: affected versions not specified; version r2 only
• Microsoft Windows Server 2012: affected versions not specified; version r2 only
• Microsoft Windows Server 2016: before 10.0.14393.8066 (fixed in 10.0.14393.8066)
• Microsoft Windows Server 2019: before 10.0.17763.7314 (fixed in 10.0.17763.7314)
• Microsoft Windows Server 2022: before 10.0.20348.3692 (fixed in 10.0.20348.3692)
• Microsoft Windows Server 2022 23h2: before 10.0.25398.1611 (fixed in 10.0.25398.1611)
• Microsoft Windows Server 2025: before 10.0.26100.3981 (fixed in 10.0.26100.3981)

Published 2025-05-13. Last modified 2026-06-17.