Actively exploited in the wild

Microsoft Windows Kernel Privilege Escalation Vulnerability

Microsoft - Windows · Listed in the CISA KEV since 2021-11-03. This indicates confirmed attacks in production environments.

Required action: Apply updates per vendor instructions.

CVE-2021-33771

HighCVSS 7.8KEV

Published: 14/07/2021(UTC)Updated: 10/08/2026(UTC)Translated: 10/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Very high risk

6.26%

93th percentile - higher than 93% of all known CVEs

Elevation of privilege vulnerability in Windows Kernel. Could be exploited to gain administrative privileges.

Potential full system compromise by a local attacker.

Install security updates released by Microsoft.

Original NVD description (English source)

Windows Kernel Elevation of Privilege Vulnerability