CVE-2025-27729: Microsoft Windows 10 21h2

High severity, CVSS 7.8. EPSS: 0.8% chance of exploitation in the next 30 days.

Use after free in Windows Shell allows an unauthorized attacker to execute code locally.

Affected products

• Microsoft Windows 10 21h2: before 10.0.19044.5737 (fixed in 10.0.19044.5737)
• Microsoft Windows 10 22h2: before 10.0.19045.5737 (fixed in 10.0.19045.5737)
• Microsoft Windows 11 22h2: before 10.0.22621.5189 (fixed in 10.0.22621.5189)
• Microsoft Windows 11 23h2: before 10.0.22631.5189 (fixed in 10.0.22631.5189)
• Microsoft Windows 11 24h2: before 10.0.26100.3775 (fixed in 10.0.26100.3775)
• Microsoft Windows Server 2025: before 10.0.26100.3775 (fixed in 10.0.26100.3775)

Published 2025-04-08. Last modified 2026-06-17.