CVE-2021-21991

7.8 highEPSS 0.3%

High (7.8) in vmware. EPSS 0.3% chance of exploitation in the next 30 days.

The vCenter Server contains a local privilege escalation vulnerability due to the way it handles session tokens. A malicious actor with non-administrative user access on vCenter Server host may exploit this issue to escalate privileges to Administrator on the vSphere Client (HTML5) or vCenter Server vSphere Web Client (FLEX/Flash).

Severity

CVSS 3.1

7.8 high

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.3% chance of exploitation in the next 30 days; higher than 24% of CVEs (scores of 2026-10-31)
Published: 2021-09-22
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

vmware:cloud_foundation
vmware:vcenter_server

References

https://www.vmware.com/security/advisories/VMSA-2021-0020.html
https://www.vmware.com/security/advisories/VMSA-2021-0020.html

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