CVE Watch—

CVE-2021-43226

Microsoft Windows Privilege Escalation Vulnerability

CVSS

—

No CVSS

EPSS

3.1%

p86

KEV

YES

Oct 6, 2025

Exploit Today

0-100

Published: — · Last modified: —

EPSS · 30d

3.1%EPSS · 30 days3.1%

2026-06-302026-07-17

KEV catalog record

Product

Microsoft / Windows

Vulnerability

Microsoft Windows Privilege Escalation Vulnerability

Added to KEV

Oct 6, 2025

Remediate by

Oct 27, 2025

Known ransomware use

Summary description

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

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.

Notes

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-43226 ; https://nvd.nist.gov/vuln/detail/CVE-2021-43226

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