Applied Cybernetics Group
Threat intel → detection pipeline
Monday, October 5, 2026
Data as of 09:42 UTC

Microsoft HTTP Protocol Stack Remote Code Execution Vulnerability

Added to KEV
2022-04-06
Federal due date
2022-04-27
Vendor
Microsoft
Product
HTTP Protocol Stack
EPSS
100.0th percentile (score 0.999, as of 2026-10-04)
NVD CVSS v3.1
—
Ransomware use
Unknown
ATT&CK
T1059 , T1190 · signal rollup
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2021-31166

CISA short description

Microsoft HTTP Protocol Stack contains a vulnerability in http.sys that allows for remote code execution.

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.