---
id: CVE-2021-33744
title: Windows Secure Kernel Mode Security Feature Bypass Vulnerability
summary: Windows Secure Kernel Mode Security Feature Bypass Vulnerability
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N'
vendor: microsoft
product: windows_10
affected:
  - windows_10 = 20h2
  - windows_10 = 21h1
  - windows_10 = 1809
  - windows_10 = 1909
  - windows_10 = 2004
  - windows_server_2016 = 20h2
  - windows_server_2016 = 2004
  - windows_server_2019
published: '2021-07-14'
updated: '2026-08-10'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-33744'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-33744'
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33744
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00787
epssPercentile: 0.54204
ingestedAt: '2026-08-10T16:41:14.669Z'
---

## Overview

Windows Secure Kernel Mode Security Feature Bypass Vulnerability

## Affected

- `windows_10 = 20h2`
- `windows_10 = 21h1`
- `windows_10 = 1809`
- `windows_10 = 1909`
- `windows_10 = 2004`
- `windows_server_2016 = 20h2`
- `windows_server_2016 = 2004`
- `windows_server_2019`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.