CVE-2023-21674: Microsoft Windows Advanced Local Procedure Call (ALPC) Privilege Escalation Vulnerability

High severity, CVSS 8.8. Actively exploited: in CISA KEV since 2023-01-10. EPSS: 41% chance of exploitation in the next 30 days.

Windows Advanced Local Procedure Call (ALPC) Elevation of Privilege Vulnerability

Affected products

• Microsoft Windows 10 1507: before 10.0.10240.19685 (fixed in 10.0.10240.19685)
• Microsoft Windows 10 1607: before 10.0.14393.5648 (fixed in 10.0.14393.5648)
• Microsoft Windows 10 1809: before 10.0.17763.3887 (fixed in 10.0.17763.3887)
• Microsoft Windows 10 20h2: before 10.0.19042.2486 (fixed in 10.0.19042.2486)
• Microsoft Windows 10 21h2: before 10.0.19044.2486 (fixed in 10.0.19044.2486)
• Microsoft Windows 10 22h2: before 10.0.19045.2486 (fixed in 10.0.19045.2486)
• Microsoft Windows 11 21h2: before 10.0.22000.1455 (fixed in 10.0.22000.1455)
• Microsoft Windows 11 22h2: before 10.0.22621.1105 (fixed in 10.0.22621.1105)
• Microsoft Windows Rt 8.1: affected versions not specified
• Microsoft Windows Server 2012: version r2 only
• Microsoft Windows Server 2016: before 10.0.14393.5648 (fixed in 10.0.14393.5648)
• Microsoft Windows Server 2019: before 10.0.17763.3887 (fixed in 10.0.17763.3887)
• Microsoft Windows Server 2022: before 10.0.20348.1487 (fixed in 10.0.20348.1487)

Published 2023-01-10. Last modified 2026-06-17.