Medium · CVSS 4.9CVE-2026-55489

BigBlueButton: IDOR on BBB through /api/graphql via POST parameter "presentationId" leads to Authentication BypassCVE-2026-55489

Answer in brief

CVE-2026-55489 records a Medium severity (CVSS 4.9) vulnerability in BigBlueButton: IDOR on BBB through /api/graphql via POST parameter "presentationId" leads to Authentication Bypass. The current sources do not mark it as known exploited. The current feed maps bigbluebutton/bigbluebutton (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 20, 2026Updated Sep 16, 2026Source checked Oct 5, 2026First seen by HOL Aug 20, 2026Material review Sep 16, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 4.9
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 4.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps bigbluebutton/bigbluebutton (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
bigbluebutton/bigbluebuttongeneric	<3.0.29	3.0.29

Recommended response

Check inventory. Check lockfiles and deployed manifests for bigbluebutton/bigbluebutton.
Review the reported fix. Update bigbluebutton/bigbluebutton to 3.0.29 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 20, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 20, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.