# CVE-2018-8399: Win32k Elevation of Privilege Vulnerability

CVE-2018-8399 is fixed in 8 products on 1 platform, first by KB4343885, released August 14, 2018. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2018-8399
- Priority: High
- CVSS: 7.0 (Important)
- EPSS: 0.0116
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Vendor exploitability assessment: Exploitation Less Likely
- Published: Aug 14, 2018
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2018-8399

## Description

<p>An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.</p> <p>To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system.</p> <p>The update addresses this vulnerability by correcting how Win32k handles objects in memory.</p>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Microsoft | Windows 10 Version 1703 for 32-bit Systems | 15063.1266 | [KB4343885](https://patchblox.com/security/data/fix/microsoft/kb4343885.md) | Aug 14, 2018 |
| Microsoft | Windows 10 Version 1703 for x64-based Systems | 15063.1266 | [KB4343885](https://patchblox.com/security/data/fix/microsoft/kb4343885.md) | Aug 14, 2018 |
| Microsoft | Windows 10 Version 1709 for 32-bit Systems | 16299.611 | [KB4343897](https://patchblox.com/security/data/fix/microsoft/kb4343897.md) | Aug 14, 2018 |
| Microsoft | Windows 10 Version 1709 for x64-based Systems | 16299.611 | [KB4343897](https://patchblox.com/security/data/fix/microsoft/kb4343897.md) | Aug 14, 2018 |
| Microsoft | Windows 10 Version 1803 for 32-bit Systems | 17134.228 | [KB4343909](https://patchblox.com/security/data/fix/microsoft/kb4343909.md) | Aug 14, 2018 |
| Microsoft | Windows 10 Version 1803 for x64-based Systems | 17134.228 | [KB4343909](https://patchblox.com/security/data/fix/microsoft/kb4343909.md) | Aug 14, 2018 |
| Microsoft | Windows Server, version 1709  (Server Core Installation) | 16299.611 | [KB4343897](https://patchblox.com/security/data/fix/microsoft/kb4343897.md) | Aug 14, 2018 |
| Microsoft | Windows Server, version 1803  (Server Core Installation) | 17134.228 | [KB4343909](https://patchblox.com/security/data/fix/microsoft/kb4343909.md) | Aug 14, 2018 |

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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