{"id":"CVE-2026-21806","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-21806","generatedAt":"2026-10-28T04:33:57.799Z","title":"HCL BigFix Service Management is affected by an Administrative Session Concurrency vulnerability.","description":"HCL BigFix Service Management is affected by an Administrative Session Concurrency vulnerability. The application allows multiple simultaneous authenticated sessions for the same administrative account, which could enable an unauthorized attacker to predict or hijack valid session identifiers. Successful exploitation allows an attacker to compromise affected administrative sessions and execute actions with full privileged user permissions.","published":"2026-09-18T12:17:24.000Z","lastModified":"2026-10-14T17:36:24.000Z","status":"Analyzed","sourceIdentifier":"psirt@hcl.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-557"],"affected":["hcltech/bigfix service management"],"epss":{"score":0.00199,"percentile":0.09637,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.20%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"scored","label":"Newly scored","at":"2026-10-14T17:45:19.000Z","detail":{"from":"3.1","score":"9.8","severity":"CRITICAL","fromSeverity":"LOW"},"summary":"Now scored CVSS 9.8 CRITICAL (was 3.1)."}],"references":[{"url":"https://support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0133592","tags":["Vendor Advisory"],"source":"psirt@hcl.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-21806","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."}