Microsoft Windows Kernel Information Disclosure Vulnerability

Added to KEV
2021-11-03
Federal due date
2021-11-17
Vendor
Microsoft
Product
Windows
EPSS
88.0th percentile (score 0.036, as of 2026-06-08)
NVD CVSS v3.1
Ransomware use
Unknown
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2021-31955

CISA short description

Microsoft Windows Kernel contains an unspecified vulnerability that allows for information disclosure. Successful exploitation allows attackers to read the contents of kernel memory from a user-mode process.

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.