Is CVE-2026-55491 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-55491?

CVE-2026-55491 has a CVSS v3 severity of MEDIUM (5.4).

Back

CVE-2026-55491

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.