CVE-2026-46351 BigBlueButton: Insecure Randomness allows to guess user's conference session token and impersonate them
Attackers can predict conference session tokens due to insecure randomness, allowing them to impersonate other users in BigBlueButton virtual classrooms.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-46351?
CVE-2026-46351 is a high-severity vulnerability in bigbluebutton, published on 16 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-330
Which versions are affected by CVE-2026-46351?
How do I fix CVE-2026-46351?
No fix has been published for CVE-2026-46351 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-46351 being exploited?
There is no known exploitation of CVE-2026-46351 in the wild and no public exploit code.
Sources
Also known as GHSA-7959-pf2v-xc4h.