CVE DATABASE / CVE-2021-43226
CVE-2021-43226
Microsoft Windows Privilege Escalation Vulnerability
CVSS 7.8 · HIGH
⚠ CISA KEV — ACTIVELY EXPLOITED
On the CISA KEV catalog
Confirmed exploited in the wild. Added 2025-10-06.
Federal remediation due 2025-10-27.
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Summary
Windows Common Log File System Driver Elevation of Privilege Vulnerability
CVSS 3.1 breakdown
| Base score | 7.8 (HIGH) |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| Attack vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity | HIGH |
| Availability | HIGH |
Affected products
Microsoft windows 10 1507Microsoft windows 10 1607Microsoft windows 10 1809Microsoft windows 10 1909Microsoft windows 10 2004Microsoft windows 10 20h2Microsoft windows 10 21h1Microsoft windows 10 21h2Microsoft windows 11 21h2Microsoft windows 7Microsoft windows 8.1Microsoft windows rt 8.1Microsoft windows server 2004Microsoft windows server 2008Microsoft windows server 2012Microsoft windows server 2016Microsoft windows server 2019Microsoft windows server 2022Microsoft windows server 20h2
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References
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43226
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-43226
Data: NIST NVD + CISA KEV. NVD last modified 2025-10-30. Always verify against the vendor advisory before acting.