# CVE-2018-8434: Windows Hyper-V Information Disclosure Vulnerability CVE-2018-8434 is fixed in 20 products on 1 platform, first by KB4457131, released September 11, 2018. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2018-8434 - Priority: Routine - CVSS: 5.4 (Important) - EPSS: 0.0349 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Vendor exploitability assessment: Exploitation Less Likely - Published: Sep 11, 2018 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2018-8434 ## Description

An information disclosure vulnerability exists when Windows Hyper-V on a host operating system fails to properly validate input from an authenticated user on a guest operating system. To exploit the vulnerability, an attacker on a guest operating system could run a specially crafted application that could cause the Hyper-V host operating system to disclose memory information.

An attacker who successfully exploited the vulnerability could gain access to information on the Hyper-V 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 | 14393.2485 | [KB4457131](https://patchblox.com/security/data/fix/microsoft/kb4457131.md) | Sep 11, 2018 | | Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1324 | [KB4457138](https://patchblox.com/security/data/fix/microsoft/kb4457138.md) | Sep 11, 2018 | | Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.665 | [KB4457142](https://patchblox.com/security/data/fix/microsoft/kb4457142.md) | Sep 11, 2018 | | Microsoft | Windows 10 Version 1803 for x64-based Systems | 17134.285 | [KB4457128](https://patchblox.com/security/data/fix/microsoft/kb4457128.md) | Sep 11, 2018 | | Microsoft | Windows 10 for x64-based Systems | 10240.17976 | [KB4457132](https://patchblox.com/security/data/fix/microsoft/kb4457132.md) | Sep 11, 2018 | | Microsoft | Windows 7 for x64-based Systems Service Pack 1 | | [KB4457144](https://patchblox.com/security/data/fix/microsoft/kb4457144.md) | Sep 11, 2018 | | Microsoft | Windows 7 for x64-based Systems Service Pack 1 | | [KB4457145](https://patchblox.com/security/data/fix/microsoft/kb4457145.md) | Sep 11, 2018 | | Microsoft | Windows 8.1 for x64-based systems | | [KB4457129](https://patchblox.com/security/data/fix/microsoft/kb4457129.md) | Sep 11, 2018 | | Microsoft | Windows 8.1 for x64-based systems | | [KB4457143](https://patchblox.com/security/data/fix/microsoft/kb4457143.md) | Sep 11, 2018 | | Microsoft | Windows RT 8.1 | | [KB4457129](https://patchblox.com/security/data/fix/microsoft/kb4457129.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 | | [KB4457144](https://patchblox.com/security/data/fix/microsoft/kb4457144.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 | | [KB4457145](https://patchblox.com/security/data/fix/microsoft/kb4457145.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) | | [KB4457144](https://patchblox.com/security/data/fix/microsoft/kb4457144.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 R2 for x64-based Systems Service Pack 1 (Server Core installation) | | [KB4457145](https://patchblox.com/security/data/fix/microsoft/kb4457145.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 | | [KB4457984](https://patchblox.com/security/data/fix/microsoft/kb4457984.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 | | [KB4458010](https://patchblox.com/security/data/fix/microsoft/kb4458010.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) | | [KB4457984](https://patchblox.com/security/data/fix/microsoft/kb4457984.md) | Sep 11, 2018 | | Microsoft | Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation) | | [KB4458010](https://patchblox.com/security/data/fix/microsoft/kb4458010.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 | | [KB4457135](https://patchblox.com/security/data/fix/microsoft/kb4457135.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 | | [KB4457140](https://patchblox.com/security/data/fix/microsoft/kb4457140.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 (Server Core installation) | | [KB4457135](https://patchblox.com/security/data/fix/microsoft/kb4457135.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 (Server Core installation) | | [KB4457140](https://patchblox.com/security/data/fix/microsoft/kb4457140.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 R2 | | [KB4457129](https://patchblox.com/security/data/fix/microsoft/kb4457129.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 R2 | | [KB4457143](https://patchblox.com/security/data/fix/microsoft/kb4457143.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 R2 (Server Core installation) | | [KB4457129](https://patchblox.com/security/data/fix/microsoft/kb4457129.md) | Sep 11, 2018 | | Microsoft | Windows Server 2012 R2 (Server Core installation) | | [KB4457143](https://patchblox.com/security/data/fix/microsoft/kb4457143.md) | Sep 11, 2018 | | Microsoft | Windows Server 2016 | 14393.2485 | [KB4457131](https://patchblox.com/security/data/fix/microsoft/kb4457131.md) | Sep 11, 2018 | | Microsoft | Windows Server 2016 (Server Core installation) | 14393.2485 | [KB4457131](https://patchblox.com/security/data/fix/microsoft/kb4457131.md) | Sep 11, 2018 | | Microsoft | Windows Server, version 1709 (Server Core Installation) | 16299.665 | [KB4457142](https://patchblox.com/security/data/fix/microsoft/kb4457142.md) | Sep 11, 2018 | | Microsoft | Windows Server, version 1803 (Server Core Installation) | 17134.285 | [KB4457128](https://patchblox.com/security/data/fix/microsoft/kb4457128.md) | Sep 11, 2018 | --- Data as of 2026-11-07T12:40:37Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo