# CVE-2018-8639: Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability

Source: https://junglewise.ai/threats/cve-2018-8639-microsoft-windows-win32k-improper-resource-shutdown-or-release  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-03-03. Updated: 2026-05-09  
License: CC BY 4.0 with a link back

CVE-2018-8639 · Severity: critical · CVSS 7.8 · Exploited in the wild · Published 2025-03-03

An elevation of privilege vulnerability exists in the Windows Win32k component due to improper handling of objects in memory. A local authenticated attacker could exploit this to run arbitrary code in kernel mode and gain elevated system privileges.

Technologies: [Microsoft Windows](https://junglewise.ai/threats/technologies/windows). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2018-8639 exploited in the wild?** Yes. CVE-2018-8639 is known to be exploited in the wild, first recorded on 3 March 2025. Treat it as urgent.

**How severe is CVE-2018-8639?** Critical severity, with a CVSS score of 7.8, published 3 March 2025.

**Which products and versions are affected?** Microsoft Windows 7 Service Pack 1; Microsoft Windows Server 2012 R2; Microsoft Windows RT 8.1; Microsoft Windows Server 2008 Service Pack 2; and 6 more.

**Is there a fix for CVE-2018-8639?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2018-8639 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2018-8639?** Check whether you run Microsoft Windows. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Microsoft Windows 7 Service Pack 1
- Microsoft Windows Server 2012 R2
- Microsoft Windows RT 8.1
- Microsoft Windows Server 2008 Service Pack 2
- Microsoft Windows Server 2019
- Microsoft Windows Server 2012
- Microsoft Windows 8.1
- Microsoft Windows Server 2016
- Microsoft Windows Server 2008 R2
- Microsoft Windows 10

## Timeline

- 2018-12-11: disclosed: Initial publication by Microsoft/NVD
- 2025-03-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2025-03-03: exploited: Confirmed as exploited in the wild per CISA KEV entry

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