Applied Cybernetics Group
Threat intel → detection pipeline
Friday, September 18, 2026
Data as of 13:09 UTC

known ransomware use

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 0.810, as of 2026-09-16)
NVD CVSS v3.1
7.8 (HIGH)
Ransomware use
Known
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.

NVD description

The kernel-mode drivers in Microsoft Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8.1, Windows Server 2012 Gold and R2, Windows RT 8.1, Windows 10 Gold, 1511, and 1607, and Windows Server 2016 allow local users to gain privileges via a crafted application, aka "Win32k Elevation of Privilege Vulnerability."

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.