CVE-2026-27737

EUVD-2026-30811
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.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
GitHub_MCNA
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
bigbluebuttonbigbluebutton
𝑥
< 3.0.19
CNA
bigbluebuttonbigbluebutton
𝑥
< 1.7.0
CNA
bigbluebuttonbigbluebutton
𝑥
< 5.4.3
CNA
Common Weakness Enumeration
Vulnerability Media Exposure
References
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/bigbluebutton/bigbluebutton/security/advisories/GHSA-8vv7-vj94-q2pv
https://github.com/blindsidenetworks/scalelite/releases/tag/v1.7.0