CVEs / CVE-2018-8639
CVE-2018-8639: Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability
- Known exploited in the CISA KEV catalog since 3 Mar 2025
- high 7.8 CVSS 3.1 (NVD)
- EPSS 22.1% chance of exploitation in the next 30 days, higher than 97% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Microsoft Windows 7 | 32-bit Systems Service Pack 1 | — |
| Microsoft Windows 7 | 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 | — |
| Microsoft Windows Server 2008 | 32-bit Systems Service Pack 2 (Server Core installation) | — |
| Microsoft Windows Server 2008 | Itanium-Based Systems Service Pack 2 | — |
| Microsoft Windows Server 2008 | x64-based Systems Service Pack 2 | — |
| Microsoft Windows Server 2008 | 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 | — |
| Microsoft Windows 8.1 | x64-based systems | — |
| Microsoft Windows Server 2016 | (Server Core installation) | — |
| Microsoft Windows Server 2008 R2 | Itanium-Based Systems Service Pack 1 | — |
| Microsoft Windows Server 2008 R2 | x64-based Systems Service Pack 1 | — |
| Microsoft Windows Server 2008 R2 | x64-based Systems Service Pack 1 (Server Core installation) | — |
| Microsoft Windows 10 | 32-bit Systems | — |
| Microsoft Windows 10 | Version 1607 for 32-bit Systems | — |
| Microsoft Windows 10 | Version 1607 for x64-based Systems | — |
| Microsoft Windows 10 | Version 1703 for 32-bit Systems | — |
| Microsoft Windows 10 | Version 1703 for x64-based Systems | — |
| Microsoft Windows 10 | Version 1709 for 32-bit Systems | — |
| Microsoft Windows 10 | Version 1709 for ARM64-based Systems | — |
| Microsoft Windows 10 | Version 1709 for x64-based Systems | — |
| Microsoft Windows 10 | Version 1803 for 32-bit Systems | — |
| Microsoft Windows 10 | Version 1803 for ARM64-based Systems | — |
| Microsoft Windows 10 | Version 1803 for x64-based Systems | — |
| Microsoft Windows 10 | Version 1809 for 32-bit Systems | — |
| Microsoft Windows 10 | Version 1809 for ARM64-based Systems | — |
Exploitation
| In CISA KEV since | 3 Mar 2025 |
|---|---|
| Due date for US federal agencies | 24 Mar 2025 |
| Used in ransomware campaigns | Known |
| 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. |
Severity
| CVSS 3.1 | 7.8 highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-404 |
References
- CVE-2018-8639 on NVD
- CVE-2018-8639 in the CISA KEV catalog
- https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2018-8639 (cited by CISA)
- http://www.securityfocus.com/bid/106093 Broken Link, Third Party Advisory, VDB Entry
- https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8639 Patch, Vendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-8639 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.