CVE-2026-34340: Microsoft Windows 10 1809

High severity, CVSS 7.0. EPSS: 0.3% chance of exploitation in the next 30 days.

Use after free in Windows Projected File System allows an authorized attacker to elevate privileges locally.

Affected products

• Microsoft Windows 10 1809: before 10.0.17763.8755 (fixed in 10.0.17763.8755)
• Microsoft Windows 10 21h2: before 10.0.19044.7291 (fixed in 10.0.19044.7291)
• Microsoft Windows 10 22h2: before 10.0.19045.7291 (fixed in 10.0.19045.7291)
• Microsoft Windows 11 23h2: before 10.0.22631.7079 (fixed in 10.0.22631.7079)
• Microsoft Windows 11 24h2: before 10.0.26100.8390 (fixed in 10.0.26100.8390)
• Microsoft Windows 11 25h2: before 10.0.26200.8390 (fixed in 10.0.26200.8390)
• Microsoft Windows 11 26h1: before 10.0.28000.2113 (fixed in 10.0.28000.2113)
• Microsoft Windows Server 2019: before 10.0.17763.8755 (fixed in 10.0.17763.8755)
• Microsoft Windows Server 2022: before 10.0.20348.5074 (fixed in 10.0.20348.5074)
• Microsoft Windows Server 2022 23h2: before 10.0.25398.2330 (fixed in 10.0.25398.2330)
• Microsoft Windows Server 2025: before 10.0.26100.32772 (fixed in 10.0.26100.32772)

Published 2026-05-12. Last modified 2026-06-17.