Windows Hyper-V Denial of Service Vulnerability
Summary
| CVE | CVE-2021-33755 |
|---|---|
| State | PUBLISHED |
| Assigner | microsoft |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2021-07-14 18:15:10 UTC |
| Updated | 2026-08-10 16:17:38 UTC |
| Description | Windows Hyper-V Denial of Service Vulnerability |
Risk And Classification
Primary CVSS: v3.1 8.6 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS: 0.031110000 probability, percentile 0.865630000 (date 2026-08-11)
Problem Types: NVD-CWE-noinfo | Denial of Service
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 8.6 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H |
| 3.1 | [email protected] | Secondary | 6.3 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 6.3 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C |
| 2.0 | [email protected] | Primary | 5 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS v2.0 Breakdown
Access Vector
NetworkAccess Complexity
LowAuthentication
NoneConfidentiality
NoneIntegrity
NoneAvailability
PartialAV:N/AC:L/Au:N/C:N/I:N/A:P
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Microsoft | Windows 10 | 1809 | All | All | All |
| Operating System | Microsoft | Windows 10 | 1909 | All | All | All |
| Operating System | Microsoft | Windows 10 | 2004 | All | All | All |
| Operating System | Microsoft | Windows 10 | 20h2 | All | All | All |
| Operating System | Microsoft | Windows 10 | 21h1 | All | All | All |
| Operating System | Microsoft | Windows Server 2016 | 2004 | All | All | All |
| Operating System | Microsoft | Windows Server 2016 | 20h2 | All | All | All |
| Operating System | Microsoft | Windows Server 2019 | - | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Microsoft | Windows 10 Version 1809 | affected 10.0.17763.0 10.0.17763.2061 custom | x64-based Systems |
| CNA | Microsoft | Windows 10 Version 1909 | affected 10.0.0 10.0.18363.1679 custom | x64-based Systems |
| CNA | Microsoft | Windows 10 Version 2004 | affected 10.0.0 10.0.19041.1110 custom | x64-based Systems |
| CNA | Microsoft | Windows 10 Version 21H1 | affected 10.0.0 10.0.19043.1110 custom | x64-based Systems |
| CNA | Microsoft | Windows Server 2019 | affected 10.0.17763.0 10.0.17763.2061 custom | x64-based Systems |
| CNA | Microsoft | Windows Server 2019 Server Core Installation | affected 10.0.17763.0 10.0.17763.2061 custom | x64-based Systems |
| CNA | Microsoft | Windows Server Version 2004 | affected 10.0.0 10.0.19041.1110 custom | x64-based Systems |
| CNA | Microsoft | Windows Server Version 20H2 | affected 10.0.0 10.0.19042.1110 custom | x64-based Systems |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| Security Update Guide - Microsoft Security Response Center | af854a3a-2127-422b-91ae-364da2661108 | portal.msrc.microsoft.com | Patch, Vendor Advisory |
| msrc.microsoft.com/update-guide/vulnerability/CVE-2021-33755 | [email protected] | msrc.microsoft.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.