CVE-2021-43226

Vulnerability overview

Windows Common Log File System Driver Elevation of Privilege Vulnerability

Severity and scoring

CVSS score

7.8 · HIGH

CVSS version

3.1

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weaknesses

NVD-CWE-noinfo

CVSS measures technical severity; it does not establish whether this vulnerability is being exploited in your environment.

Known exploitation and remediation

Listed in CISA’s Known Exploited Vulnerabilities catalog.

Affected product

Microsoft · Windows

Added to catalog

2025-10-06

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 remediation due date

2025-10-27

CISA deadlines apply to the organizations covered by its directives. Confirm your own remediation requirements.

Verify affected versions and patch availability in the vendor advisory before making changes.

Affected products and versions

• cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x64:*

  Before (exclusive): 10.0.10240.19145

• cpe:2.3:o:microsoft:windows_10_1507:*:*:*:*:*:*:x86:*

  Before (exclusive): 10.0.10240.19145

• cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*

  Before (exclusive): 10.0.14393.4825

• cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*

  Before (exclusive): 10.0.14393.4825

• cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.17763.2366

• cpe:2.3:o:microsoft:windows_10_1909:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.18363.1977

• cpe:2.3:o:microsoft:windows_10_2004:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.19041.1415

• cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:arm64:*

  Before (exclusive): 10.0.19042.1415

• cpe:2.3:o:microsoft:windows_10_20h2:*:*:*:*:*:*:x86:*

  Before (exclusive): 10.0.19042.1415

• cpe:2.3:o:microsoft:windows_10_21h1:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.19043.1415

• cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.19044.1415

• cpe:2.3:o:microsoft:windows_11_21h2:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.22000.376

• cpe:2.3:o:microsoft:windows_7:-:sp1:*:*:*:*:*:*

• cpe:2.3:o:microsoft:windows_8.1:-:*:*:*:*:*:*:*

• cpe:2.3:o:microsoft:windows_rt_8.1:-:*:*:*:*:*:*:*

• cpe:2.3:o:microsoft:windows_server_2004:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.19041.1415

• cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x64:*

• cpe:2.3:o:microsoft:windows_server_2008:-:sp2:*:*:*:*:x86:*

• cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:*:*:*:*:x64:*

• cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*

• cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*

• cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.14393.4825

• cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.17763.2366

• cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.20348.405

• cpe:2.3:o:microsoft:windows_server_20h2:*:*:*:*:*:*:*:*

  Before (exclusive): 10.0.19042.1415

These are NVD CPE applicability entries. Some products depend on configuration conditions; consult the official record to confirm applicability.

Advisories and references

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43226

  Patch · Vendor Advisory

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43226

  Patch · Vendor Advisory

• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-43226

  US Government Resource

Explore official sources

Read the official NVD record ↗

Explore the CISA catalog ↗

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