---
id: "CVE-2018-8639"
kind: "vulnerability"
aliases: ["CVE-2018-8639"]
title: "An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects\u2026"
severity: "high"
cvss: 8.4
epss: null
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Microsoft Windows", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1507", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1607", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1703", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1709", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1803", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 10 1809", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 7", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows 8.1", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows rt 8.1", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows server 2008", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows server 2008", "fixed": [], "affected": "= r2", "ecosystem": "vendor"}, {"name": "microsoft windows server 2012", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows server 2012", "fixed": [], "affected": "= r2", "ecosystem": "vendor"}, {"name": "microsoft windows server 2016", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft windows server 2019", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "multi-user-systems", "ransomware", "windows", "windows-servers"]
not_affected_if: ["no-local-user-access"]
published_at: "2018-12-12T00:29:01+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T22:29:05+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-8639", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-8639", "first_seen_at": "2026-10-23T22:29:05+00:00"}]
---

# An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects…

A flaw in the Windows Win32k kernel component lets a logged-in local user release resources improperly and gain privilege escalation. A successful attacker can run arbitrary code in kernel mode, and the sources report it is exploited in the wild, including by ransomware operators.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft Windows affected ? fixed ?
- vendor:microsoft windows 10 1507 affected ? fixed ?
- vendor:microsoft windows 10 1607 affected ? fixed ?
- vendor:microsoft windows 10 1703 affected ? fixed ?
- vendor:microsoft windows 10 1709 affected ? fixed ?
- vendor:microsoft windows 10 1803 affected ? fixed ?
- vendor:microsoft windows 10 1809 affected ? fixed ?
- vendor:microsoft windows 7 affected ? fixed ?
- vendor:microsoft windows 8.1 affected ? fixed ?
- vendor:microsoft windows rt 8.1 affected ? fixed ?
- vendor:microsoft windows server 2008 affected ? fixed ?
- vendor:microsoft windows server 2008 affected = r2 fixed ?
- vendor:microsoft windows server 2012 affected ? fixed ?
- vendor:microsoft windows server 2012 affected = r2 fixed ?
- vendor:microsoft windows server 2016 affected ? fixed ?
- vendor:microsoft windows server 2019 affected ? fixed ?

## Fix

Apply the Microsoft mitigation for CVE-2018-8639 for your Windows version, per CISA's required action; the specific patch KB is not stated in the sources.
If no mitigation is available, discontinue use of the affected product.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-8639
- 2026-10-23T22:29:05+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2018-8639

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_