CVE-2021-43226
HighActively exploited (CISA KEV)Known to be used in ransomware campaigns
Description
Windows Common Log File System Driver Elevation of Privilege Vulnerability
SeverityHigh
CVSS7.8
Exploit probability—
Product
Microsoft Windows
PublishedDec 15, 2021
First seenDec 15, 2021
Added to KEVOct 6, 2025
How to fix
CISA 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.
CISA due date: Oct 27, 2025Update
- microsoft windows_10_150710.0.10240.19145 or later
- microsoft windows_10_160710.0.14393.4825 or later
- microsoft windows_10_180910.0.17763.2366 or later
- microsoft windows_10_190910.0.18363.1977 or later
- microsoft windows_10_200410.0.19041.1415 or later
- microsoft windows_10_20h210.0.19042.1415 or later
- microsoft windows_10_21h110.0.19043.1415 or later
- microsoft windows_10_21h210.0.19044.1415 or later
- microsoft windows_11_21h210.0.22000.376 or later
- microsoft windows_server_200410.0.19041.1415 or later
- microsoft windows_server_201610.0.14393.4825 or later
- microsoft windows_server_201910.0.17763.2366 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| microsoft windows_10_1507 | v < 10.0.10240.19145 | 10.0.10240.19145 |
| microsoft windows_10_1607 | v < 10.0.14393.4825 | 10.0.14393.4825 |
| microsoft windows_10_1809 | v < 10.0.17763.2366 | 10.0.17763.2366 |
| microsoft windows_10_1909 | v < 10.0.18363.1977 | 10.0.18363.1977 |
| microsoft windows_10_2004 | v < 10.0.19041.1415 | 10.0.19041.1415 |
| microsoft windows_10_20h2 | v < 10.0.19042.1415 | 10.0.19042.1415 |
| microsoft windows_10_21h1 | v < 10.0.19043.1415 | 10.0.19043.1415 |
| microsoft windows_10_21h2 | v < 10.0.19044.1415 | 10.0.19044.1415 |
| microsoft windows_11_21h2 | v < 10.0.22000.376 | 10.0.22000.376 |
| microsoft windows_7 | No range specified | — |
| microsoft windows_8.1 | No range specified | — |
| microsoft windows_rt_8.1 | No range specified | — |
| microsoft windows_server_2004 | v < 10.0.19041.1415 | 10.0.19041.1415 |
| microsoft windows_server_2008 | No range specified, r2 | — |
| microsoft windows_server_2012 | No range specified, r2 | — |
| microsoft windows_server_2016 | v < 10.0.14393.4825 | 10.0.14393.4825 |
| microsoft windows_server_2019 | v < 10.0.17763.2366 | 10.0.17763.2366 |
| microsoft windows_server_2022 | v < 10.0.20348.405 | 10.0.20348.405 |
| microsoft windows_server_20h2 | v < 10.0.19042.1415 | 10.0.19042.1415 |
Check your version
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