CVE-2026-66804: Microsoft Windows 10 22h2

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

Improper access control in Windows Cross Device Service allows an authorized attacker to elevate privileges locally.

Affected products

• Microsoft Windows 10 22h2: before 10.0.19045.7663 (fixed in 10.0.19045.7663)
• Microsoft Windows 11 24h2: before 10.0.26100.9106 (fixed in 10.0.26100.9106)
• Microsoft Windows 11 25h2: before 10.0.26200.9106 (fixed in 10.0.26200.9106)
• Microsoft Windows 11 26h1: before 10.0.28000.2704 (fixed in 10.0.28000.2704)

Published 2026-08-11. Last modified 2026-08-14.