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

known ransomware use

VMware vCenter Server Remote Code Execution Vulnerability

Added to KEV
2021-11-03
Federal due date
2021-11-17
Vendor
VMware
Product
vCenter Server
EPSS
100.0th percentile (score 0.999, as of 2026-09-16)
NVD CVSS v3.1
9.8 (CRITICAL)
Ransomware use
Known
ATT&CK
T1059 , T1190 · signal rollup
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2021-21972

CISA short description

VMware vCenter Server vSphere Client contains a remote code execution vulnerability in a vCenter Server plugin which allows an attacker with network access to port 443 to execute commands with unrestricted privileges on the underlying operating system.

Required action

Apply updates per vendor instructions.

NVD description

The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server. This affects VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).

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.