# CVE-2026-55489: BigBlueButton presentation deletion authorization bypass

Source: https://junglewise.ai/threats/cve-2026-55489-bigbluebutton-presentation-deletion-authorization-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-20. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-55489 · Severity: medium · CVSS 4.9 · Published 2026-08-20

BigBlueButton is an open-source video conferencing platform used for virtual meetings and distance learning. A presenter with knowledge of another meeting's presentation ID could delete presentations from other meetings without authorization, disrupting those sessions. The vulnerability allows cross-meeting presentation sabotage without requiring authentication to the target meeting.

Technologies: [BigBlueButton](https://junglewise.ai/threats/technologies/bigbluebutton). Vendors: [BigBlueButton](https://junglewise.ai/threats/vendors/bigbluebutton).

## Quick answers

**Is CVE-2026-55489 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-55489 being exploited in the wild.

**How severe is CVE-2026-55489?** Medium severity, with a CVSS score of 4.9, published 20 August 2026.

**Which products and versions are affected?** BigBlueButton prior to 3.0.29.

**Is there a fix for CVE-2026-55489?** A patch was published on 2026-06-12: Version 3.0.29 released with fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-55489 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-55489?** Check whether you run BigBlueButton at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is an authorization bypass in the RemovePresentationPubMsgHdlr.scala component that handles presentation deletion via the GraphQL API endpoint (/api/graphql). The root cause is missing meeting ID verification before deleting a presentation—when a presenter submits a presentationId, the system fails to validate that the presentation belongs to their own meeting. An authenticated presenter with knowledge of another meeting's presentation ID can exploit this by submitting it to delete the foreign presentation, even though they are not part of that meeting. The vulnerability was patched in version 3.0.29 by adding meeting ID verification checks in the deletion handler.

## Affected products

- BigBlueButton BigBlueButton prior to 3.0.29

## Timeline

- 2026-06-12: patched: Version 3.0.29 released with fix
- 2026-08-20: disclosed

## References

- [https://github.com/bigbluebutton/bigbluebutton/commit/c9e93f9af07b9661e286d101b83cbccb891c551f](https://github.com/bigbluebutton/bigbluebutton/commit/c9e93f9af07b9661e286d101b83cbccb891c551f)
- [https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29](https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29)

## Related threats

- [BigBlueButton stored XSS in recording playback](https://junglewise.ai/threats/cve-2026-55491-bigbluebutton-stored-xss-in-recording-playback)
- [BigBlueButton SQL injection in breakout room visibility query](https://junglewise.ai/threats/cve-2026-46682-bigbluebutton-sql-injection-in-breakout-room-visibility-query)
- [BigBlueButton authentication bypass in API controller](https://junglewise.ai/threats/cve-2026-46355-bigbluebutton-authentication-bypass-in-api-controller)
- [BigBlueButton SSRF in presentation URL validation](https://junglewise.ai/threats/cve-2026-46404-bigbluebutton-ssrf-in-presentation-url-validation)
- [BigBlueButton bbb-web checksum bypass in API request handling](https://junglewise.ai/threats/cve-2026-46353-bigbluebutton-bbb-web-checksum-bypass-in-api-request-handling)