# CVE-2021-43226

Windows Common Log File System Driver Elevation of Privilege Vulnerability

- Page: https://www.vulneraibility.com/cve/CVE-2021-43226
- CVSS: 7.8
- Known exploited: yes, in CISA KEV since 2025-10-06; CISA due date 2025-10-27; known ransomware use
- EPSS: 3.28%
- Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept (first 2023-10-30)
- CISA SSVC: exploitation active, automatable no, technical impact total (assessed 2021-12-16)
- Published: 2021-12-15

## Affected versions

- Microsoft Windows 10 Version 1507: affected >= 10.0.0 and < 10.0.10240.19145
- Microsoft Windows 10 Version 1607: affected >= 10.0.0 and < 10.0.14393.4825
- Microsoft Windows 10 Version 1809: affected >= 10.0.0 and < 10.0.17763.2366
- Microsoft Windows 10 Version 1909: affected >= 10.0.0 and < 10.0.18363.1977
- Microsoft Windows 10 Version 2004: affected >= 10.0.0 and < 10.0.19041.1415
- Microsoft Windows 10 Version 20H2: affected >= 10.0.0 and < 10.0.19042.1415
- Microsoft Windows 10 Version 21H1: affected >= 10.0.0 and < 10.0.19043.1415
- Microsoft Windows 10 Version 21H2: affected >= 10.0.0 and < 10.0.19044.1415
- Microsoft Windows 11 version 21H2: affected >= 10.0.0 and < 10.0.22000.376
- Microsoft Windows 7: affected >= 6.1.0 and < 6.1.7601.25796
- Microsoft Windows 7 Service Pack 1: affected >= 6.1.0 and < 6.1.7601.25796
- Microsoft Windows 8.1: affected >= 6.3.0 and < 6.3.9600.20207
- Microsoft Windows Server 2008 R2 Service Pack 1: affected >= 6.1.0 and < 6.1.7601.25796
- Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation): affected >= 6.0.0 and < 6.1.7601.25796
- Microsoft Windows Server 2008 Service Pack 2: affected >= 6.0.0 and < 6.0.6003.21309
- Microsoft Windows Server 2008  Service Pack 2: affected >= 6.0.0 and < 6.0.6003.21309
- Microsoft Windows Server 2008 Service Pack 2 (Server Core installation): affected >= 6.0.0 and < 6.0.6003.21309
- Microsoft Windows Server 2012: affected >= 6.2.0 and < 6.2.9200.23545; >= 6.2.0 and < 6.2.9200.23540
- Microsoft Windows Server 2012 R2: affected >= 6.3.0 and < 6.3.9600.20207
- Microsoft Windows Server 2012 R2 (Server Core installation): affected >= 6.3.0 and < 6.3.9600.20207
- Microsoft Windows Server 2012 (Server Core installation): affected >= 6.2.0 and < 6.2.9200.23545; >= 6.2.0 and < 6.2.9200.23540
- Microsoft Windows Server 2016: affected >= 10.0.0 and < 10.0.14393.4825
- Microsoft Windows Server 2016 (Server Core installation): affected >= 10.0.0 and < 10.0.14393.4825
- Microsoft Windows Server 2019: affected >= 10.0.0 and < 10.0.17763.2366
- Microsoft Windows Server 2019 (Server Core installation): affected >= 10.0.0 and < 10.0.17763.2366
- Microsoft Windows Server 2022: affected >= 10.0.0 and < 10.0.20348.405
- Microsoft Windows Server version 2004: affected >= 10.0.0 and < 10.0.19041.1415
- Microsoft Windows Server version 20H2: affected >= 10.0.0 and < 10.0.19042.1415

A version outside these ranges is not a statement that it is unaffected.

## References

- [other] https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43226
- [other] https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-43226

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.