CVE-2026-46355
BigBlueButton: Unauthenticated Session Hijack via Exposed /bigbluebutton/api/handleJoinExistingUser
- State
- Published
- Severity
- 7.1 High
- Published
- Aug 20, 2026
- Updated
- Aug 25, 2026
- Reserved
- May 13, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.1 High | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N | GitHub_M |
Weaknesses
- CWE-287 Improper Authentication
Affected Products
| Product | Versions |
|---|---|
bigbluebuttonbigbluebutton |
|
References
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