Low severity · published Feb 21, 2026
CVE-2026-27467
BigBlueButton: Audio from participants to the server initially unmuted
2.4
CVSS
0.2%
EPSS
No
On KEV
Description
BigBlueButton is an open-source virtual classroom. In versions 3.0.19 and below, when first joining a session with the microphone muted, the client sends audio to the server regardless of mute state. Media is discarded at the server side, so it isn't audible to any participants, but this may allow for malicious server operators to access audio data. The behavior is only incorrect between joining the meeting and the first time the user unmutes. This issue has been fixed in version 3.0.20.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
Required
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 11% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BI
bigbluebutton · bigbluebutton
< 3.0.20 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-27467
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-27467
Patch
https://github.com/bigbluebutton/bigbluebutton/commit/3aa47832bc2b17178799bd932453c226e8f95703
Patch
https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-6gj9-5rhm-68j8
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