BigBlueButton up to 3.0.28 index.html.erb meetingName cross site scripting

Summaryinfo

A vulnerability was found in BigBlueButton up to 3.0.28. It has been classified as problematic. Affected is an unknown function of the file record-and-playback/screenshare/playback/index.html.erb. Performing a manipulation of the argument meetingName results in cross site scripting. This vulnerability is cataloged as CVE-2026-55491. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in BigBlueButton up to 3.0.28. It has been classified as problematic. This affects an unknown code block of the file record-and-playback/screenshare/playback/index.html.erb. The manipulation of the argument meetingName with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-55491 since 06/17/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

Upgrading to version 3.0.29 eliminates this vulnerability.

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Productinfo

Name

• BigBlueButton

Version

• 3.0.0
• 3.0.1
• 3.0.2
• 3.0.3
• 3.0.4
• 3.0.5
• 3.0.6
• 3.0.7
• 3.0.8
• 3.0.9
• 3.0.10
• 3.0.11
• 3.0.12
• 3.0.13
• 3.0.14
• 3.0.15
• 3.0.16
• 3.0.17
• 3.0.18
• 3.0.19
• 3.0.20
• 3.0.21
• 3.0.22
• 3.0.23
• 3.0.24
• 3.0.25
• 3.0.26
• 3.0.27
• 3.0.28

License

• free

Website

• Product: https://github.com/bigbluebutton/bigbluebutton/

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