CVE-2021-31955: Microsoft Windows Kernel Information Disclosure Vulnerability

Medium severity, CVSS 5.5. Actively exploited: in CISA KEV since 2021-11-03. EPSS: 81.1% chance of exploitation in the next 30 days.

Windows Kernel Information Disclosure Vulnerability

Affected products

• Microsoft Windows 10 1809: before 10.0.17763.1999 (fixed in 10.0.17763.1999)
• Microsoft Windows 10 1909: before 10.0.18363.1621 (fixed in 10.0.18363.1621)
• Microsoft Windows 10 2004: before 10.0.19041.1052 (fixed in 10.0.19041.1052)
• Microsoft Windows 10 20h2: before 10.0.19042.1052 (fixed in 10.0.19042.1052)
• Microsoft Windows 10 21h1: before 10.0.19043.1052 (fixed in 10.0.19043.1052)
• Microsoft Windows Server 2004: before 10.0.19041.1052 (fixed in 10.0.19041.1052)
• Microsoft Windows Server 2019: before 10.0.17763.1999 (fixed in 10.0.17763.1999)
• Microsoft Windows Server 20h2: before 10.0.19042.1052 (fixed in 10.0.19042.1052)

Published 2021-06-08. Last modified 2026-06-17.