CVE-2026-46351
HIGHBigBlueButton: Insecure Randomness allows to guess user's conference session token and impersonate them
Title source: cnaDescription
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 (3)
Core 3
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-7959-pf2v-xc4h
X_Refsource_Misc x_refsource_misc
https://github.com/bigbluebutton/bigbluebutton/commit/8457886c248aeba5597ee8749267602d6d117e98
X_Refsource_Misc x_refsource_misc
https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.21
Scores
CVSS v3
8.1
EPSS
0.0026
EPSS Percentile
17.5%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
total
Details
CWE
CWE-330
Status
published
Products (1)
bigbluebutton/bigbluebutton
< 3.0.21
Published
Jul 16, 2026
Tracked Since
Jul 17, 2026