CVE-2026-20940: Microsoft Windows 10 1607

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

Heap-based buffer overflow in Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally.

Affected products

• Microsoft Windows 10 1607: before 10.0.14393.8783 (fixed in 10.0.14393.8783)
• Microsoft Windows 10 1809: before 10.0.17763.8276 (fixed in 10.0.17763.8276)
• Microsoft Windows 10 21h2: before 10.0.19044.6809 (fixed in 10.0.19044.6809)
• Microsoft Windows 10 22h2: before 10.0.19045.6809 (fixed in 10.0.19045.6809)
• Microsoft Windows 11 23h2: before 10.0.22631.6491 (fixed in 10.0.22631.6491)
• Microsoft Windows Server 2008: affected versions not specified; version r2 only
• Microsoft Windows Server 2012: affected versions not specified; version r2 only
• Microsoft Windows Server 2016: before 10.0.14393.8783 (fixed in 10.0.14393.8783)
• Microsoft Windows Server 2019: before 10.0.17763.8276 (fixed in 10.0.17763.8276)
• Microsoft Windows Server 2022: before 10.0.20348.4648 (fixed in 10.0.20348.4648)

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