Exploited· due 2025-03-24used in ransomware

CVE-2018-8639

Microsoft Windows

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.

Exploitation status

  • CISA has confirmed this is being exploited in the wild. That is an observation of real attacks, not a prediction.
  • It is known to have been used in ransomware campaigns.
  • US federal civilian agencies are required to remediate it by 2025-03-24. That deadline does not bind private companies, but it is a reasonable benchmark for how urgently CISA views it.

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.

CISA’s wording, unedited.

Scoring

CVSS
Not yet scored

Dates

Published
2025-03-03
Added to KEV
2025-03-03
Remediation due
2025-03-24
Sources
CISA KEV