CVE-2021-42278: Microsoft Active Directory Domain Services Privilege Escalation Vulnerability

High severity, CVSS 7.5. Actively exploited: in CISA KEV since 2022-04-11. EPSS: 73.3% chance of exploitation in the next 30 days.

Active Directory Domain Services Elevation of Privilege Vulnerability

Affected products

• Microsoft Windows Server 2004: before 10.0.19041.1348 (fixed in 10.0.19041.1348)
• 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 10.0.14393.4770 (fixed in 10.0.14393.4770)
• Microsoft Windows Server 2019: before 10.0.17763.2300 (fixed in 10.0.17763.2300)
• Microsoft Windows Server 2022: before 10.0.20348.350 (fixed in 10.0.20348.350)
• Microsoft Windows Server 20h2: before 10.0.19042.1348 (fixed in 10.0.19042.1348)

Published 2021-11-10. Last modified 2026-08-19.