High 8.1Published Jul 16, 2026

CVE-2026-46351BigBlueButton: Insecure Randomness allows to guess user's conference session token and impersonate them

Updated under an hour ago (Oct 26, 2026, 11:50 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for bigbluebutton

Exploited in the last 30 days

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.

CVSS: 8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE): CWE-330
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Jul 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

bigbluebutton bigbluebutton bigbluebutton:bigbluebutton (from the name)	before 3.0.21	CNA record

References

References

https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-7959-pf2v-xc4h	x-refsource-confirm
https://github.com/bigbluebutton/bigbluebutton/commit/8457886c248aeba5597ee8749267602d6d117e98	x-refsource-misc
https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.21	x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.