CVE-2026-55489 BigBlueButton: IDOR on BBB through /api/graphql via POST parameter "presentationId" leads to Authentication Bypass
Attackers can delete presentations from other meetings by manipulating the presentationId parameter, disrupting service availability.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-55489?
CVE-2026-55489 is a medium-severity missing authorization vulnerability in bigbluebutton, published on 20 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton presenters could submit a presentationId through /api/graphql that identified a presentation belonging to another meeting. akka-bbb-apps/src/main/scala/org/bigbluebutton/core/apps/presentationpod/RemovePresentationPubMsgHdlr.scala did not verify the presentation's meeting identifier before deletion, allowing a presenter who knew the identifier to delete another meeting's presentation and disrupt its availability. This issue is fixed in version 3.0.29.
Weakness: CWE-639
Which versions are affected by CVE-2026-55489?
How do I fix CVE-2026-55489?
No fix has been published for CVE-2026-55489 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-55489 being exploited?
There is no known exploitation of CVE-2026-55489 in the wild and no public exploit code.
Sources
Also known as GHSA-jxpq-r3h3-p75g.