CVE-2018-8639

HIGH

7.8

CVSS Score

Published: December 12, 2018 at 12:00 AM UTC

Updated: June 17, 2026 at 02:05 AM UTC

14 products affected across 1 vendorWindows Server 2016Windows Server 2019Windows Server 2012

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Severity

HIGH7.8

Exploitation

CISA KEV

Exploit prediction

EPSS 22%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score22.2%

EPSS (Exploit Prediction Scoring System) estimates a 22.2% chance this CVE is exploited in the wild within the next 30 days — higher than 98% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

Microsoft Windows Win32k contains an improper resource shutdown or release vulnerability that allows for local, authenticated privilege escalation. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode.

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.

Ransomware Use

Known

Added to KEV

Mar 3, 2025

Remediation Due

Mar 24, 2025

582 days overdue

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.