CVE-2026-55491
BigBlueButton: Stored XSS in Screenshare Recording Playback via Unescaped Meeting Name
- State
- Published
- Severity
- 5.4 Medium
- Published
- Aug 20, 2026
- Updated
- Aug 21, 2026
- Reserved
- Jun 16, 2026
Description
BigBlueButton is an open-source virtual classroom. Prior to 3.0.29, BigBlueButton failed to escape meetingName in record-and-playback/screenshare/playback/index.html.erb when generating the screenshare playback format. A low-privileged user could store a crafted meeting name that embedded script content, and the script executed in another user's browser when that user replayed the recording. This issue is fixed in version 3.0.29.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.4 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N | GitHub_M |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
bigbluebuttonbigbluebutton |
|
References
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