March 3, 2025 · Applied Cybernetics Group
CVE-2018-8639 — Microsoft Windows
known ransomware use
Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability
- Added to KEV
2025-03-03- Federal due date
2025-03-24- Vendor
- Microsoft
- Product
- Windows
- EPSS
- 97.0th percentile (score 0.332, as of
2026-06-08) - NVD CVSS v3.1
- —
- Ransomware use
- Known
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2018-8639
CISA short 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.
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.