How severe is CVE-2018-8639?

CVE-2018-8639 has a CVSS 3.1 base score of 8.4 (HIGH). EPSS estimates a 22.2% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

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

CISA Known Exploited Vulnerabilities

Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2025-03-03

Remediation due

2025-03-24

Ransomware

Known use

Required action
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 notes
https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2018-8639 ; https://nvd.nist.gov/vuln/detail/CVE-2018-8639

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.

Severity

CVSS 3.1 · CISA8.4 HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Affected Products

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

References

2 Links

Vulnerability databases

106093

Other references

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8639

Record Details

Published

2018-12-12

Last updated

2025-10-21

Assigner (CNA)

microsoft

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.