---
id: CVE-2021-33755
title: Windows Hyper-V Denial of Service Vulnerability
summary: Windows Hyper-V Denial of Service Vulnerability
severity: medium
cvss: 6.3
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H'
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-2021-33755'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-33755'
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-33755
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.03111
epssPercentile: 0.87267
ingestedAt: '2026-08-10T16:41:15.119Z'
---

## Overview

Windows Hyper-V Denial of Service 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.