Vulnerabilities/VMware/CVE-2021-21985

CVE-2021-21985: VMware vCenter Server Improper Input Validation Vulnerability

CISA KEV entry · Last checked 30 Oct 2026, 12:10 UTC

Exploitation confirmedRansomware use knownFix: Unknown

CVSS 3.1 · NVD9.8Critical
EPSS100.0%100th percentile · 29 Oct 2026
CISA KEVListedAdded 3 Nov 2021

VMware vSphere Client contains an improper input validation vulnerability in the Virtual SAN Health Check plug-in, which is enabled by default in vCenter Server, which allows for remote code execution.

Recommended action

Apply updates per vendor instructions.

CISA due date 17 Nov 2021 · CWE-20, CWE-470, CWE-918

Am I affected?

ProductAffected versionsFixed in
VMware vCenter Server and VMware Cloud FoundationVMware vCenter Server (7.x before 7.0 U2b, 6.7 before 6.7 U3n, 6.5 before 6.5 U3p) and VMware Cloud Foundation (4.x before 4.2.1, 3.x before 3.10.2.1)Unknown

No source states a fixed version. Check the vendor advisory below.

Before you patch

Restart

See vendor guidance.

Known issues

Check release notes.

Verification

Confirm installed version.

Timeline

  • 3 Nov 2021 · Added to CISA KEV
  • 17 Nov 2021 · CISA due date

References

Sources checked
CISA KEV30 Oct 2026, 12:10 UTC
CVE List v530 Oct 2026, 12:10 UTC
NVD30 Oct 2026, 12:10 UTC
FIRST EPSS30 Oct 2026, 12:11 UTC

Data from CISA, MITRE, NVD and FIRST. Sources and licences.