{"id":"CVE-2026-46355","state":"PUBLISHED","title":"BigBlueButton: Unauthenticated Session Hijack via Exposed /bigbluebutton/api/handleJoinExistingUser","description":"BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, BigBlueButton exposed /bigbluebutton/api/handleJoinExistingUser through bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy. A requester able to supply an existingUserID for an active participant could reuse that participant's session and impersonate the participant in the same meeting because handleJoinExistingUser was a routable controller action rather than a private helper. This issue is fixed in version 3.0.23.","publishedAt":"2026-08-20T21:34:40.529Z","updatedAt":"2026-08-25T15:26:14.221Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["bigbluebutton bigbluebutton"],"affected":[{"vendor":"bigbluebutton","product":"bigbluebutton","versions":[{"version":"< 3.0.23","status":"affected"}]}],"references":["https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-38fw-2gq7-ccgr","https://github.com/bigbluebutton/bigbluebutton/commit/972b04e474e195cbd708b5b3f0485fe528a1a85b","https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.23"],"weaknesses":["CWE-287"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46355.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46355","state":"PUBLISHED","datePublished":"2026-08-20T21:34:40.529Z","dateUpdated":"2026-08-25T15:26:14.221Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-13T18:37:30.991Z"},"containers":{"cna":{"title":"BigBlueButton: Unauthenticated Session Hijack via Exposed /bigbluebutton/api/handleJoinExistingUser","descriptions":[{"lang":"en","value":"BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, BigBlueButton exposed /bigbluebutton/api/handleJoinExistingUser through bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy. A requester able to supply an existingUserID for an active participant could reuse that participant's session and impersonate the participant in the same meeting because handleJoinExistingUser was a routable controller action rather than a private helper. This issue is fixed in version 3.0.23."}],"affected":[{"vendor":"bigbluebutton","product":"bigbluebutton","versions":[{"version":"< 3.0.23","status":"affected"}]}],"references":[{"url":"https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-38fw-2gq7-ccgr","name":"https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-38fw-2gq7-ccgr","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/bigbluebutton/bigbluebutton/commit/972b04e474e195cbd708b5b3f0485fe528a1a85b","name":"https://github.com/bigbluebutton/bigbluebutton/commit/972b04e474e195cbd708b5b3f0485fe528a1a85b","tags":["x_refsource_MISC"]},{"url":"https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.23","name":"https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.23","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"LOW","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-287","lang":"en","description":"CWE-287: Improper Authentication","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-20T21:34:40.529Z"},"source":{"advisory":"GHSA-38fw-2gq7-ccgr","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-25T15:26:02.501669Z","id":"CVE-2026-46355","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-25T15:26:14.221Z"}}]}}}