CVE-2026-27737
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.
Published:May 18, 2026
Last Modified:May 19, 2026
EPS:May 18, 2026
EPSS Score:0.00032
CVSS Score:6.5
Affected Products
Vendor
Product
Action
Vendor
Bigbluebutton
Product
Bbb-playback
Bigbluebutton
Bbb-playback
Vendor
Bigbluebutton
Product
Bigbluebutton
Bigbluebutton
Bigbluebutton
Vendor
Blindsidenetworks
Product
Scalite
Blindsidenetworks
Scalite
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
References
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
