November 3, 2021 · Applied Cybernetics Group
CVE-2021-36955 — Microsoft Windows
known ransomware use
Microsoft Windows Common Log File System (CLFS) Driver Privilege Escalation Vulnerability
- Added to KEV
2021-11-03- Federal due date
2021-11-17- Vendor
- Microsoft
- Product
- Windows
- EPSS
- 86.8th percentile (score 0.032, as of
2026-07-13) - NVD CVSS v3.1
- —
- Ransomware use
- Known
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2021-36955
CISA short description
Microsoft Windows Common Log File System (CLFS) driver contains an unspecified vulnerability that allows for privilege escalation.
Required action
Apply updates per vendor instructions.