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Findings

CVE-2021-43226

Microsoft Windows Privilege Escalation Vulnerability

Published Dec 15, 2021 · updated Aug 21, 2026 · Microsoft Windows

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

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Dec 15, 2021 · Catalog

    Detected

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

  2. Oct 6, 2025 · CISA KEV

    Known exploited

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  3. Oct 27, 2025 · CISA KEV

    Remediation due

    Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

  4. Aug 21, 2026 · Catalog

    Updated

    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.

CISA due date Oct 27, 2025

Affected

  • cpe microsoft/windows 10 1507version unspecified
  • cpe microsoft/windows 10 1607version unspecified
  • cpe microsoft/windows 10 1809version unspecified
  • cpe microsoft/windows 10 1909version unspecified
  • cpe microsoft/windows 10 2004version unspecified
  • cpe microsoft/windows 10 20h2version unspecified
  • vendor Microsoft Windowsversion unspecified

Sources

  • CISA KEVConfirmed exploitationCVE-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.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2021-43226

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2021-43226

    30-day exploitation probability 3.3%

    first.org
  • NIST NVDVulnerability recordCVE-2021-43226

    Windows Common Log File System Driver Elevation of Privilege Vulnerability

    nvd.nist.gov

References