CVE-2026-27737
BigBlueButton has Stored XSS in bbb-playback replay
- State
- Published
- Severity
- 6.5 Medium
- Published
- May 18, 2026
- Updated
- May 19, 2026
- Reserved
- Feb 23, 2026
Description
BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.19, the recording playback (presentation format) was not sanitizing user's input in public chat. This allowed for a malicious actor to craft and carry out a targeted XSS attack, activated on anyone replaying the recording. This issue has been fixed 3.0.19.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 6.5 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N | GitHub_M |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
bigbluebuttonbigbluebutton |
|
scaliteblindsidenetworks |
|
bbb-playbackbigbluebutton |
|
References
- https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-8vv7-vj94-q2pv
- https://github.com/bigbluebutton/bbb-playback/commit/09e89bfe4ff8488b68c3ff040d3081e419dc89b1
- https://github.com/bigbluebutton/bigbluebutton/commit/69f45aa1b963dc7d80179d0155acc670aec5c4fc
- https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.19
- https://github.com/blindsidenetworks/scalelite/releases/tag/v1.7.0
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