On 2025-03-03, CISA added CVE-2018-8639 (Microsoft Windows) to its Known Exploited Vulnerabilities (KEV) catalog [2]. The vulnerability is listed in the catalog as "Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability" [2]. CISA requires applying mitigations in accordance with vendor instructions; see the full text below for specific requirements [2].
Backfill: this event became public on Mar 3, 2025 and we added it on Nov 10, 2026. It is not a new event.
CISA Adds Microsoft Windows Vulnerability CVE-2018-8639 to Known Exploited Vulnerabilities Catalog
1 min read
- Disclosed
- Mar 3, 2025
- Published
- Nov 10, 2026
- Last updated
- Nov 8, 2026
- CVSS basis
- Our assessment
- 22.3%, higher than 98% of CVEs
- Exploitation and patch status
- ExploitedKEV
- Attack vector
- Vulnerability status
- Actor type
- Motivation
On this page
30-second summary
What happened
Who is affected
Industries mainly affected: Government, Cross-industry
What to do nowOur advice
CISA requires applying mitigations in accordance with vendor instructions; see the full text for specific requirements [2].
Timeline
Technical details
CISA KEV Listing
On 2025-03-03, CISA added CVE-2018-8639 to the Known Exploited Vulnerabilities () catalog for Microsoft Windows [2].
Original Technical Description
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. [2]
Official Requirements
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. [2]
Individual Vulnerability Record
The U.S. National Vulnerability Database (NVD) provides an independent vulnerability record and description for CVE-2018-8639 [1].
References
Official / primary3
- [1]
“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 ”
- [2]
This site aggregates public information and is not security consulting advice. Test remediation steps before applying.