Microsoft Win32k Privilege Escalation Vulnerability

Added to KEV
2021-11-03
Federal due date
2022-05-03
Vendor
Microsoft
Product
Win32k
EPSS
99.6th percentile (score 0.894, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2016-7255

CISA short description

Microsoft Win32k kernel-mode driver fails to properly handle objects in memory which allows for privilege escalation. Successful exploitation allows an attacker to run code in kernel mode.

Required action

Apply updates per vendor instructions.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.