Vulnerability · Published Aug 20, 2026 · Assigned by GitHub_M

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

Medium 4.9

In plain English

A medium-severity authorization bypass via user-controlled key in bigbluebutton from bigbluebutton. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 3.1)4.9Medium

Exploit odds (30 days)0.3%top 75.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
bigbluebutton	bigbluebutton	< 3.0.29

Weakness: CWE-639 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:L

References

https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-jxpq-r3h3-p75g x_refsource_CONFIRM
https://github.com/bigbluebutton/bigbluebutton/commit/c9e93f9af07b9661e286d101b83cbccb891c551f x_refsource_MISC
https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.29 x_refsource_MISC