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

Microsoft Win32k Privilege Escalation Vulnerability

Added to KEV
2021-11-03
Federal due date
2022-05-03
Vendor
Microsoft
Product
Win32k
EPSS
99.0th percentile (score 0.542, as of 2026-09-16)
NVD CVSS v3.1
7 (HIGH)
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2020-1054

CISA short description

Microsoft Win32k contains a privilege escalation vulnerability when the Windows kernel-mode driver fails to properly handle objects in memory. Successful exploitation allows an attacker to execute code in kernel mode.

Required action

Apply updates per vendor instructions.

NVD description

An elevation of privilege vulnerability exists in Windows when the Windows kernel-mode driver fails to properly handle objects in memory. An attacker who successfully exploited this vulnerability could run arbitrary code in kernel mode. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights. To exploit this vulnerability, an attacker would first have to log on to the system. An attacker could then run a specially crafted application that could exploit the vulnerability and take control of an affected system. The update addresses this vulnerability by correcting how the Windows kernel-mode driver handles objects in memory.

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.