{"id":"CVE-2021-21986","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-21986","generatedAt":"2026-11-05T01:17:37.678Z","title":"The vSphere Client (HTML5) contains a vulnerability in a vSphere authentication mechanism for the Virtual SAN Health Check, Site Recovery, vSphere Lifecycle Manager, and VMware Cloud Director Availability plug-ins.","description":"The vSphere Client (HTML5) contains a vulnerability in a vSphere authentication mechanism for the Virtual SAN Health Check, Site Recovery, vSphere Lifecycle Manager, and VMware Cloud Director Availability plug-ins. A malicious actor with network access to port 443 on vCenter Server may perform actions allowed by the impacted plug-ins without authentication.","published":"2021-05-26T15:15:08.000Z","lastModified":"2026-06-17T03:36:30.000Z","status":"Modified","sourceIdentifier":"security@vmware.com","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-306"],"affected":["vmware/vcenter server","vmware/cloud foundation"],"epss":{"score":0.13265,"percentile":0.9639,"date":"2026-11-03","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 13.3%, higher than 96% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html","tags":["Third Party Advisory","VDB Entry"],"source":"security@vmware.com"},{"url":"https://www.vmware.com/security/advisories/VMSA-2021-0010.html","tags":["Vendor Advisory"],"source":"security@vmware.com"},{"url":"http://packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.html","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.vmware.com/security/advisories/VMSA-2021-0010.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-21986","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}