CVE-2021-21972: listed in the CISA KEV catalog

CVE-2021-21972 · CVSS 9.8 CRITICAL · EPSS 99.9% · KEV 2021-11-03

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).

Is CVE-2021-21972 exploited?

• Listed in the CISA KEV catalog on 2021-11-03.
• Federal remediation due 2021-11-17.
• Past that date by 1808 days.
• Used in ransomware campaigns.
• EPSS puts exploitation in the next 30 days at 99.9%.
• Public exploit code: packaged in a public tool.
• Public detection rules exist.

Which products and versions are affected?

• VMware vCenter Server · 7.x before 7.0 U1c, 6.7 before 6.7 U3l, 6.5 before 6.5 U3n
• VMware Cloud Foundation · 4.x before 4.2, 3.x before 3.10.1.2

Is there a patch?

Patch information is not available in this record.

What PlainSec published about CVE-2021-21972

• Google Cloud split its patch duty in two (2026-08-26)
• Node kernel bugs on GKE COS nodes enable host escalation (2026-04-15)
• Google Cloud issues multiple Linux kernel privilege escalation fixes for GKE nodes (2026-04-07)
• Multiple Linux Kernel Flaws Elevate Privileges on GCP Container Nodes (2026-04-03)
• Multiple High-Severity Cloud Vulnerabilities Impact Container Nodes (2026-04-01)

Primary sources

• NVD record
• CISA KEV catalog
• VMware vCenter Server advisory
• Metasploit: exploit/multi/http/vmware_vcenter_uploadova_rce
• Exploit-DB 50056
• Exploit-DB 49602
• Nuclei template

What this record does not say

• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-09-13.