# CVE-2020-16891: Windows Hyper-V Remote Code Execution Vulnerability CVE-2020-16891 is fixed in 25 products on 1 platform, first by KB4580346, released October 13, 2020. It is not reported as exploited. Patch Radar priority: Urgent. - Web page: https://patchblox.com/security/cve/CVE-2020-16891 - Priority: Urgent - CVSS: 8.8 (Critical) - EPSS: 0.0095 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Vendor exploitability assessment: Exploitation Less Likely - Published: Oct 13, 2020 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2020-16891 ## Description

A remote code execution vulnerability exists when Windows Hyper-V on a host server fails to properly validate input from an authenticated user on a guest operating system. To exploit the vulnerability, an attacker could run a specially crafted application on a guest operating system that could cause the Hyper-V host operating system to execute arbitrary code.

An attacker who successfully exploited the vulnerability could execute arbitrary code on the host operating system.

The security update addresses the vulnerability by correcting how Hyper-V validates guest operating system user input.

## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Windows 10 Version 1607 for x64-based Systems | 14393.3986 | [KB4580346](https://patchblox.com/security/data/fix/microsoft/kb4580346.md) | Oct 13, 2020 | | Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.2166 | [KB4580328](https://patchblox.com/security/data/fix/microsoft/kb4580328.md) | Oct 13, 2020 | | Microsoft | Windows 10 Version 1803 for x64-based Systems | 17134.1792 | [KB4580330](https://patchblox.com/security/data/fix/microsoft/kb4580330.md) | Oct 13, 2020 | | Microsoft | Windows 10 Version 1809 for x64-based Systems | 17763.1518 | [KB4577668](https://patchblox.com/security/data/fix/microsoft/kb4577668.md) | Oct 13, 2020 | | Microsoft | Windows 10 Version 1903 for x64-based Systems | | [KB4577671](https://patchblox.com/security/data/fix/microsoft/kb4577671.md) | Oct 13, 2020 | | Microsoft | Windows 10 Version 1909 for x64-based Systems | | [KB4577671](https://patchblox.com/security/data/fix/microsoft/kb4577671.md) | Oct 13, 2020 | | Microsoft | Windows 10 Version 2004 for x64-based Systems | 19041.572 | [KB4579311](https://patchblox.com/security/data/fix/microsoft/kb4579311.md) | Oct 13, 2020 | | Microsoft | Windows 10 for x64-based Systems | 10240.18725 | [KB4580327](https://patchblox.com/security/data/fix/microsoft/kb4580327.md) | Oct 13, 2020 | | Microsoft | Windows 7 for x64-based Systems Service Pack 1 | | [KB4580345](https://patchblox.com/security/data/fix/microsoft/kb4580345.md) | Oct 13, 2020 | | Microsoft | Windows 7 for x64-based Systems Service Pack 1 | | [KB4580387](https://patchblox.com/security/data/fix/microsoft/kb4580387.md) | Oct 13, 2020 | | Microsoft | Windows 8.1 for x64-based systems | | [KB4580358](https://patchblox.com/security/data/fix/microsoft/kb4580358.md) | Oct 13, 2020 | | Microsoft | Windows 8.1 for x64-based systems | | [KB4580347](https://patchblox.com/security/data/fix/microsoft/kb4580347.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 | | [KB4580345](https://patchblox.com/security/data/fix/microsoft/kb4580345.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 | | [KB4580387](https://patchblox.com/security/data/fix/microsoft/kb4580387.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) | | [KB4580345](https://patchblox.com/security/data/fix/microsoft/kb4580345.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) | | [KB4580387](https://patchblox.com/security/data/fix/microsoft/kb4580387.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 | | [KB4580378](https://patchblox.com/security/data/fix/microsoft/kb4580378.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 | | [KB4580385](https://patchblox.com/security/data/fix/microsoft/kb4580385.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) | | [KB4580378](https://patchblox.com/security/data/fix/microsoft/kb4580378.md) | Oct 13, 2020 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) | | [KB4580385](https://patchblox.com/security/data/fix/microsoft/kb4580385.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 | | [KB4580382](https://patchblox.com/security/data/fix/microsoft/kb4580382.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 | | [KB4580353](https://patchblox.com/security/data/fix/microsoft/kb4580353.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 (Server Core installation) | | [KB4580382](https://patchblox.com/security/data/fix/microsoft/kb4580382.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 (Server Core installation) | | [KB4580353](https://patchblox.com/security/data/fix/microsoft/kb4580353.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 R2 | | [KB4580358](https://patchblox.com/security/data/fix/microsoft/kb4580358.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 R2 | | [KB4580347](https://patchblox.com/security/data/fix/microsoft/kb4580347.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 R2 (Server Core installation) | | [KB4580358](https://patchblox.com/security/data/fix/microsoft/kb4580358.md) | Oct 13, 2020 | | Microsoft | Windows Server 2012 R2 (Server Core installation) | | [KB4580347](https://patchblox.com/security/data/fix/microsoft/kb4580347.md) | Oct 13, 2020 | | Microsoft | Windows Server 2016 | 14393.3986 | [KB4580346](https://patchblox.com/security/data/fix/microsoft/kb4580346.md) | Oct 13, 2020 | | Microsoft | Windows Server 2016 (Server Core installation) | 14393.3986 | [KB4580346](https://patchblox.com/security/data/fix/microsoft/kb4580346.md) | Oct 13, 2020 | | Microsoft | Windows Server 2019 | 17763.1518 | [KB4577668](https://patchblox.com/security/data/fix/microsoft/kb4577668.md) | Oct 13, 2020 | | Microsoft | Windows Server 2019 (Server Core installation) | 17763.1518 | [KB4577668](https://patchblox.com/security/data/fix/microsoft/kb4577668.md) | Oct 13, 2020 | | Microsoft | Windows Server, version 1903 (Server Core installation) | | [KB4577671](https://patchblox.com/security/data/fix/microsoft/kb4577671.md) | Oct 13, 2020 | | Microsoft | Windows Server, version 1909 (Server Core installation) | | [KB4577671](https://patchblox.com/security/data/fix/microsoft/kb4577671.md) | Oct 13, 2020 | | Microsoft | Windows Server, version 2004 (Server Core installation) | 19041.572 | [KB4579311](https://patchblox.com/security/data/fix/microsoft/kb4579311.md) | Oct 13, 2020 | --- Data as of 2026-11-09T07:25:28Z UTC. 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