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

> CVE-2018-8639: Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability. CVSS 8.4 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2018-8639
Last updated: 2025-10-21T23:45:46Z

- Published: 2018-12-12 00:00 UTC · Updated: 2025-10-21 23:45 UTC · Assigner: microsoft
- CVSS: 8.4 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS: 22.2%, 98th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2025-03-03, federal due date 2025-03-24, ransomware use: Known

## 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.

## CISA 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.

## Affected vendors and products

- Microsoft: Windows 10
- Microsoft: Windows 10 Servers
- Microsoft: Windows 7
- Microsoft: Windows 8.1
- Microsoft: Windows RT 8.1
- Microsoft: Windows Server 2008
- Microsoft: Windows Server 2008 R2
- Microsoft: Windows Server 2012
- Microsoft: Windows Server 2012 R2
- Microsoft: Windows Server 2016
- Microsoft: Windows Server 2019

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2018-8639)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2018-8639)
- [https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8639](https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8639)
- [http://www.securityfocus.com/bid/106093](http://www.securityfocus.com/bid/106093)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2018-8639 · Markdown: https://rewindex.com/cve/CVE-2018-8639.md · JSON: https://rewindex.com/api/v1/cves/CVE-2018-8639 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:48:28.108Z