CVE-2026-46355
Published:August 20, 2026
Updated:September 24, 2026
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 Packages
https://github.com/bigbluebutton/bigbluebutton.git (GITHUB):
Affected version(s) >=v3.0.1 <v3.0.23Fix Suggestion:
Update to version v3.0.23Related Resources (5)
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Contact UsCVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
LOW
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
LOW
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Improper Authentication
EPSS
Base Score:
0.21