# CVE-2018-8634: Microsoft Text-To-Speech Remote Code Execution Vulnerability CVE-2018-8634 is fixed in 21 products on 1 platform, first by KB4471321, released December 11, 2018. It is not reported as exploited, but the vendor rates exploitation more likely. Patch Radar priority: Urgent. - Web page: https://patchblox.com/security/cve/CVE-2018-8634 - Priority: Urgent - CVSS: 4.2 (Critical) - EPSS: 0.1536 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Vendor exploitability assessment: Exploitation More Likely - Published: Dec 11, 2018 - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2018-8634 ## Description

A remote code execution vulnerability exists in Windows where Microsoft text-to-speech fails to properly handle objects in the memory. An attacker who successfully exploited this vulnerability could take control of the affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. Users whose accounts are configured to have fewer user rights on the system could be less impacted than users who operate with administrative user rights.

The security update addresses the vulnerability by correcting how the Microsoft text-to-speech handles objects in the memory.

## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Windows 10 Version 1607 for 32-bit Systems | 14393.2665 | [KB4471321](https://patchblox.com/security/data/fix/microsoft/kb4471321.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1607 for x64-based Systems | 14393.2665 | [KB4471321](https://patchblox.com/security/data/fix/microsoft/kb4471321.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.1506 | [KB4471327](https://patchblox.com/security/data/fix/microsoft/kb4471327.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1506 | [KB4471327](https://patchblox.com/security/data/fix/microsoft/kb4471327.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.846 | [KB4471329](https://patchblox.com/security/data/fix/microsoft/kb4471329.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1709 for ARM64-based Systems | 16299.846 | [KB4471329](https://patchblox.com/security/data/fix/microsoft/kb4471329.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.846 | [KB4471329](https://patchblox.com/security/data/fix/microsoft/kb4471329.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1803 for 32-bit Systems | 17134.471 | [KB4471324](https://patchblox.com/security/data/fix/microsoft/kb4471324.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1803 for ARM64-based Systems | 17134.471 | [KB4471324](https://patchblox.com/security/data/fix/microsoft/kb4471324.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1803 for x64-based Systems | 17134.471 | [KB4471324](https://patchblox.com/security/data/fix/microsoft/kb4471324.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1809 for 32-bit Systems | 17763.194 | [KB4471332](https://patchblox.com/security/data/fix/microsoft/kb4471332.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1809 for ARM64-based Systems | 17763.194 | [KB4471332](https://patchblox.com/security/data/fix/microsoft/kb4471332.md) | Dec 11, 2018 | | Microsoft | Windows 10 Version 1809 for x64-based Systems | 17763.194 | [KB4471332](https://patchblox.com/security/data/fix/microsoft/kb4471332.md) | Dec 11, 2018 | | Microsoft | Windows 10 for 32-bit Systems | 10240.18063 | [KB4471323](https://patchblox.com/security/data/fix/microsoft/kb4471323.md) | Dec 11, 2018 | | Microsoft | Windows 10 for x64-based Systems | 10240.18063 | [KB4471323](https://patchblox.com/security/data/fix/microsoft/kb4471323.md) | Dec 11, 2018 | | Microsoft | Windows Server 2016 | 14393.2665 | [KB4471321](https://patchblox.com/security/data/fix/microsoft/kb4471321.md) | Dec 11, 2018 | | Microsoft | Windows Server 2016 (Server Core installation) | 14393.2665 | [KB4471321](https://patchblox.com/security/data/fix/microsoft/kb4471321.md) | Dec 11, 2018 | | Microsoft | Windows Server 2019 | 17763.194 | [KB4471332](https://patchblox.com/security/data/fix/microsoft/kb4471332.md) | Dec 11, 2018 | | Microsoft | Windows Server 2019 (Server Core installation) | 17763.194 | [KB4471332](https://patchblox.com/security/data/fix/microsoft/kb4471332.md) | Dec 11, 2018 | | Microsoft | Windows Server, version 1709 (Server Core Installation) | 16299.846 | [KB4471329](https://patchblox.com/security/data/fix/microsoft/kb4471329.md) | Dec 11, 2018 | | Microsoft | Windows Server, version 1803 (Server Core Installation) | 17134.471 | [KB4471324](https://patchblox.com/security/data/fix/microsoft/kb4471324.md) | Dec 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