⚠ Actively exploited
Added to CISA KEV on 2025-10-06. Federal agencies required to patch by 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..

CVE-2021-43226

6 documents6 sources
Severity
7.8HIGH
EPSS
8.4%
top 7.68%
CISA KEV
KEV
Added 2025-10-06
Due 2025-10-27
Exploit
Exploited in wild
Active exploitation observed
Affected products
39
Microsoft Windows 10 Version 1507Microsoft Windows 10 Version 1607Microsoft Windows 10 Version 1809+36 more
Timeline
PublishedDec 15
KEV addedOct 6
KEV dueOct 27
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.

Description

Windows Common Log File System Driver Elevation of Privilege Vulnerability

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitability: 1.8 | Impact: 5.9

Affected Packages37 packages

▶NVDmicrosoft/windows< 10.0.19041.1415+5
▶CVEListV5microsoft/windows_76.1.0 — 6.1.7601.25796
▶CVEListV5microsoft/windows_8.16.3.0 — 6.3.9600.20207
▶NVDmicrosoft/windows_10_1507< 10.0.10240.19145
▶NVDmicrosoft/windows_10_1607< 10.0.14393.4825

Patches

Patch: portal.msrc.microsoft.com ↗Patch: portal.msrc.microsoft.com ↗

🔴Vulnerability Details

3
GHSA
GHSA-98jh-5xvm-p5ph: Windows Common Log File System Driver Elevation of Privilege Vulnerability This CVE ID is unique from CVE-2021-43207↗2021-12-16
▶
CVEList
Windows Common Log File System Driver Elevation of Privilege Vulnerability↗2021-12-15
▶
VulnCheck
Microsoft Windows Privilege Escalation Vulnerability↗2021
▶

📋Vendor Advisories

2
CISA
Microsoft Windows Privilege Escalation Vulnerability↗2025-10-06
▶
Microsoft
Windows Common Log File System Driver Elevation of Privilege Vulnerability↗2021-12-14
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CVE-2021-43226 (HIGH CVSS 7.8) | Windows Common Log File System Driv | cvebase.io