CVE-2026-55491
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.
Does this matter?
Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.4 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.17% probability · 6th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.