HackZoneLabs News
Newsletter

CVE-2018-8639

Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability

  • High 8.4
  • Exploited: added to CISA KEV 3 Mar 2025
  • Used in ransomware campaigns

Description

An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in memory, aka "Win32k Elevation of Privilege Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2019, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers. This CVE ID is unique from CVE-2018-8641.

Key facts

Published
12 Dec 2018
Last changed
21 Oct 2025
Assigned by
microsoft
KEV added
3 Mar 2025
KEV fix due
24 Mar 2025
Used in ransomware
Yes, according to CISA
EPSS
22.349% likely to be exploited in the next 30 days, higher than 97.728% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: active; Automatable: no; Technical impact: total

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 8.4CVSS 3.1, Highfrom CISA (ADP container)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What to do

  • Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.CISA KEV required action

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
MicrosoftWindows 7
  • 32-bit Systems Service Pack 1 (affected)
  • x64-based Systems Service Pack 1 (affected)
MicrosoftWindows Server 2012 R2
  • (Server Core installation) (affected)
MicrosoftWindows RT 8.1
  • Windows RT 8.1 (affected)
MicrosoftWindows Server 2008
  • 32-bit Systems Service Pack 2 (affected)
  • 32-bit Systems Service Pack 2 (Server Core installation) (affected)
  • Itanium-Based Systems Service Pack 2 (affected)
  • x64-based Systems Service Pack 2 (affected)
  • x64-based Systems Service Pack 2 (Server Core installation) (affected)
MicrosoftWindows Server 2019
  • (Server Core installation) (affected)
MicrosoftWindows Server 2012
  • (Server Core installation) (affected)
MicrosoftWindows 8.1
  • 32-bit systems (affected)
  • x64-based systems (affected)
MicrosoftWindows Server 2016
  • (Server Core installation) (affected)
MicrosoftWindows Server 2008 R2
  • Itanium-Based Systems Service Pack 1 (affected)
  • x64-based Systems Service Pack 1 (affected)
  • x64-based Systems Service Pack 1 (Server Core installation) (affected)
MicrosoftWindows 10
  • 32-bit Systems (affected)
  • Version 1607 for 32-bit Systems (affected)
  • Version 1607 for x64-based Systems (affected)
  • Version 1703 for 32-bit Systems (affected)
  • Version 1703 for x64-based Systems (affected)
  • Version 1709 for 32-bit Systems (affected)
  • Version 1709 for ARM64-based Systems (affected)
  • Version 1709 for x64-based Systems (affected)
  • Version 1803 for 32-bit Systems (affected)
  • Version 1803 for ARM64-based Systems (affected)
  • Version 1803 for x64-based Systems (affected)
  • Version 1809 for 32-bit Systems (affected)
  • Version 1809 for ARM64-based Systems (affected)
  • Version 1809 for x64-based Systems (affected)
  • x64-based Systems (affected)
MicrosoftWindows 10 Servers
  • version 1709 (Server Core Installation) (affected)
  • version 1803 (Server Core Installation) (affected)

Timeline

  1. 12 Dec 2018 Published
  2. 3 Mar 2025 CVE-2018-8639 added to CISA KEV
  3. 3 Mar 2025 Added to the CISA KEV catalogue

Weakness

References