[ CVE-2021-43226 · Published 15 Dec 2021 ]
Microsoft Windows Privilege Escalation Vulnerability
Exploited · CISA KEV CVSS 7.8
EPSS 3%Fix available
[ Why it matters ]Priority signals
- Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2025-10-06
- Known to be used in ransomware campaigns
[ Description ]Official description
Windows Common Log File System Driver Elevation of Privilege Vulnerability
CISA: Microsoft Windows Common Log File System Driver contains a privilege escalation vulnerability that could allow a local, privileged attacker to bypass certain security mechanisms.
[ Fixes ]Fixes and patches
CISA required action (US federal deadline 27 Oct 2025): Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- Patch on portal.msrc.microsoft.comVendor patch or bulletin · NVD · Reference tagged 'Patch' by NVD
[ References ]References
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43226PatchVendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource