CVE-2026-46351
BigBlueButton: Insecure Randomness allows to guess user's conference session token and impersonate them
CVSS Score
8.1
EPSS Score
0.0%
EPSS Percentile
0th
BigBlueButton is an open-source virtual classroom. Prior to 3.0.21, bbb-web generated conference sessionToken values with insufficiently secure randomness in bbb-common-web/src/main/java/org/bigbluebutton/api/Util.java and bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy, allowing a session user to predict other users' conference session tokens and impersonate them. This issue is fixed in version 3.0.21.
| CWE | CWE-330 |
| Vendor | bigbluebutton |
| Product | bigbluebutton |
| Published | Jul 16, 2026 |
| Last Updated | Jul 16, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Affected Versions
bigbluebutton / bigbluebutton
< 3.0.21