Microsoft Windows Win32k Improper Resource Shutdown or Release Vulnerability (CVE-2018-8639)
Severity: high · Patch status: patched · Since 2025-03-03 · CVE-2018-8639
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. CISA added CVE-2018-8639 to its Known Exploited Vulnerabilities catalog on Mar 3, 2025, which means attackers are exploiting it in the wild. CISA reports known use in ransomware campaigns.
What to do
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- US federal agencies must remediate by Mar 24, 2025 (BOD 22-01); treat that as the outer limit.
Sources
All live incidents on Threat Watch
