CVE-2026-46351

HIGH8.1

BigBlueButton: Insecure Randomness allows to guess user's conference session token and impersonate them

Published Jul 16, 2026

Modified 1 months ago

Details

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.

References

WEB

https://github.com/bigbluebutton/bigbluebutton/commit/8457886c248aeba5597ee8749267602d6d117e98

WEB

https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.21

WEB

https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-7959-pf2v-xc4h

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-46351

CVSS Analysis

CVSS v3.1

8.1