HIGHCVSS 7.8Actively exploited · CISA KEV since 2025-10-06Vulnerability

CVE-2021-43226

Microsoft Windows Common Log File System Driver contains a privilege escalation vulnerability that could allow a local, privileged attacker to bypass certain security mechanisms.

Properties

Euvd product
Windows Server 2008 Service Pack 2, Windows 7, Windows 11 version 21H2, Windows 10 Version 21H2, Windows 10 Version 1507, Windows Server 2019, Windows 7 Service Pack 1, Windows Server version 20H2, Windows 10 Version 21H1, Windows Server 2022, Windows 8.1, Windows Server 2012, Windows Server 2012 R2, Windows Server 2012 (Server Core installation), Windows Server 2008 R2 Service Pack 1, Windows Server 2012 R2 (Server Core installation), Windows Server version 2004, Windows Server 2019 (Server Core installation), Windows 10 Version 1809, Windows 10 Version 20H2, Windows Server 2016, Windows 10 Version 2004, Windows Server 2008 R2 Service Pack 1 (Server Core installation), Windows Server 2016 (Server Core installation), Windows 10 Version 1607
Vulnerability name
Microsoft Windows Privilege Escalation Vulnerability
First seen
2026-08-22T03:55:15+00:00
Cvss score
7.8
Epss score
0.03275
Last seen
2026-10-19T12:00:27+00:00
Due date
2025-10-27
Euvd assigner
microsoft
Retrieved at
2026-10-21T01:24:47+00:00
Exploited euvd since
2025-10-06T00:00:00+00:00
Src batch id
epss_history-20261020T103617Z-728ddd
Source url
https://epss.empiricalsecurity.com/epss_scores-2026-10-19.csv.gz
Date added
2025-10-06
Euvd base score version
3.1
Score
7.8
Fetched at
2026-10-20T10:36:20+00:00
Euvd vendor
Microsoft
Cvss vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
In Signal since
initial import (Sep 2026)
Euvd base score
7.8

Related Entities (27 · showing 22)

AFFECTS_PRODUCT (25 · showing 20)

→[Product]cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:x86:*
→[Product]cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:arm64:*
→[Product]cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*
→[Product]cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x86:*
→[Product]cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:*
→[Product]cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
→[Product]cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
→[Product]cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x64:*
→[Product]cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*
→[Product]cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:*

DESCRIBES (1)

←[KEVEntry]Microsoft Windows Privilege Escalation Vulnerability

INVOLVES (1)

←[Signal]kev_added · 2025-10-06

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CVE-2021-43226 (CVSS 7.8) — Ninja Signal Threat Intelligence | Ninja Signal