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.
History

Thu, 20 Aug 2026 23:15:00 +0000

Type Values Removed Values Added
First Time appeared Bigbluebutton
Bigbluebutton bigbluebutton
Vendors & Products Bigbluebutton
Bigbluebutton bigbluebutton

Thu, 20 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
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.
Title BigBlueButton: Unauthenticated Session Hijack via Exposed /bigbluebutton/api/handleJoinExistingUser
Weaknesses CWE-287
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-08-20T21:34:40.529Z

Updated: 2026-08-20T21:34:40.529Z

Reserved: 2026-05-13T18:37:30.991Z

Link: CVE-2026-46355

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-20T22:17:19.193

Modified: 2026-08-20T22:17:19.193

Link: CVE-2026-46355

cve-icon Redhat

No data.