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

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. 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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