CVE-2026-55491
Medium
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.
SeverityMedium
CVSS5.4
Exploit probability—
ProductBigbluebutton
PublishedAug 20, 2026
First seenAug 20, 2026
Weakness typeCWE-79Cross-site scripting (XSS)
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| bigbluebutton bigbluebutton | < 3.0.29 | — |
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