CVE-2026-27737
BigBlueButton has Stored XSS in bbb-playback replay
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-79 |
| Vendor | bigbluebutton |
| Product | bigbluebutton |
| Published | May 18, 2026 |
| Last Updated | May 19, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
Affected Versions
bigbluebutton / bigbluebutton
< 3.0.19
blindsidenetworks / scalite
< 1.7.0
bigbluebutton / bbb-playback
< 5.4.3
References
github.com: https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-8vv7-vj94-q2pv github.com: https://github.com/bigbluebutton/bbb-playback/commit/09e89bfe4ff8488b68c3ff040d3081e419dc89b1 github.com: https://github.com/bigbluebutton/bigbluebutton/commit/69f45aa1b963dc7d80179d0155acc670aec5c4fc github.com: https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.19 github.com: https://github.com/blindsidenetworks/scalelite/releases/tag/v1.7.0