CVE-2026-27737

BigBlueButton has Stored XSS in bbb-playback replay

Published May 18, 2026 CVSS 3.1 · 6.5 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Bigbluebutton
Bigbluebutton bbb-playback
Bigbluebutton bigbluebutton
Blindsidenetworks
Blindsidenetworks scalite
Vendors & Products Bigbluebutton
Bigbluebutton bbb-playback
Bigbluebutton bigbluebutton
Blindsidenetworks
Blindsidenetworks scalite
Type Values Removed Values Added
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.
Title BigBlueButton has Stored XSS in bbb-playback replay
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 19, 2026, 12:11 PM
Reserved
Feb 23, 2026, 6:37 PM
Status
Deferred
Published
May 18, 2026, 10:16 PM
Modified
Jul 24, 2026, 1:10 PM