CVE-2026-46355

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data tampering.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-08-20 22:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-26 10:10 UTC Last updatedMost recent change to the record

Details

Published

2026-08-20 22:17 UTC

Last modified

2026-10-26 10:10 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-287 · Improper authentication

Record status

Deferred

Attack profile CVSS 3.1 · 7.1

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

None