CVE-2025-21334: Microsoft Windows Hyper-V NT Kernel Integration VSP Use-After-Free Vulnerability

High severity, CVSS 7.8. Actively exploited: in CISA KEV since 2025-01-14. EPSS: 1.6% chance of exploitation in the next 30 days.

Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability

Affected products

• Microsoft Windows 10 21h2: before 10.0.19044.5371 (fixed in 10.0.19044.5371)
• Microsoft Windows 10 22h2: before 10.0.19045.5371 (fixed in 10.0.19045.5371)
• Microsoft Windows 11 22h2: before 10.0.22621.4751 (fixed in 10.0.22621.4751)
• Microsoft Windows 11 23h2: before 10.0.22631.4751 (fixed in 10.0.22631.4751)
• Microsoft Windows 11 24h2: before 10.0.26100.2894 (fixed in 10.0.26100.2894)
• Microsoft Windows Server 2022 23h2: before 10.0.25398.1369 (fixed in 10.0.25398.1369)
• Microsoft Windows Server 2025: before 10.0.26100.2894 (fixed in 10.0.26100.2894)

Published 2025-01-14. Last modified 2026-06-17.