Description
BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.19, the recording playback (presentation format) was not sanitizing user's input in public chat. This allowed for a malicious actor to craft and carry out a targeted XSS attack, activated on anyone replaying the recording. This issue has been fixed 3.0.19.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| bigbluebutton | bigbluebutton | < 3.0.19 | — |
| blindsidenetworks | scalite | < 1.7.0 | — |
| bigbluebutton | bbb-playback | < 5.4.3 | — |
Advisories 1
- WID-SEC-2026-1501 BigBlueButton: Schwachstelle ermöglicht Cross-Site Scripting BSI CERT-Bund (WID) · May 18, 2026
References
- https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-8vv7-vj94-q2pv
- https://github.com/bigbluebutton/bbb-playback/commit/09e89bfe4ff8488b68c3ff040d3081e419dc89b1
- https://github.com/bigbluebutton/bigbluebutton/commit/69f45aa1b963dc7d80179d0155acc670aec5c4fc
- https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.19
- https://github.com/blindsidenetworks/scalelite/releases/tag/v1.7.0