November 3, 2021 · Applied Cybernetics Group
CVE-2021-33771 — Microsoft Windows
Microsoft Windows Kernel Privilege Escalation Vulnerability
- Added to KEV
2021-11-03- Federal due date
2021-11-17- Vendor
- Microsoft
- Product
- Windows
- EPSS
- 95.4th percentile (score 0.102, as of
2026-09-16) - NVD CVSS v3.1
- 7.8 (HIGH)
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2021-33771
CISA short description
Microsoft Windows kernel contains an unspecified vulnerability that allows for privilege escalation.
Required action
Apply updates per vendor instructions.
NVD description
Windows Kernel Elevation of Privilege Vulnerability