CVE-2021-43217: Microsoft Windows 10

Critical severity, CVSS 9.8. EPSS: 6.5% chance of exploitation in the next 30 days.

Windows Encrypting File System (EFS) Remote Code Execution Vulnerability

Affected products

• Microsoft Windows 10: affected versions not specified; version 20h2 only; version 21h1 only; version 1607 only; version 1809 only; version 1909 only; …
• Microsoft Windows 11: affected versions not specified
• Microsoft Windows 7: affected versions not specified
• Microsoft Windows 8.1: affected versions not specified
• Microsoft Windows Rt 8.1: affected versions not specified
• Microsoft Windows Server: version 20h2 only; version 2022 only
• 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: affected versions not specified; version 2004 only
• Microsoft Windows Server 2019: affected versions not specified

Published 2021-12-15. Last modified 2026-06-17.