CVE-2026-20870: Microsoft Windows 11 24h2

High severity, CVSS 7.8. EPSS: 0.5% chance of exploitation in the next 30 days.

Use after free in Windows Win32K - ICOMP allows an authorized attacker to elevate privileges locally.

Affected products

• Microsoft Windows 11 24h2: before 10.0.26100.7623 (fixed in 10.0.26100.7623)
• Microsoft Windows 11 25h2: before 10.0.26200.7623 (fixed in 10.0.26200.7623)
• Microsoft Windows Server 2025: before 10.0.26100.32230 (fixed in 10.0.26100.32230)

Published 2026-01-13. Last modified 2026-07-30.