CVE-2026-27737
Medium
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.
SeverityMedium
CVSS6.5
Exploit probability—
ProductBigbluebutton
PublishedMay 18, 2026
First seenMay 18, 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 | < 3.0.19 | — |
| blindsidenetworks scalite | < 1.7.0 | — |
| bigbluebutton bbb-playback | < 5.4.3 | — |
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