Bigbluebutton
CVE-2026-27467
LOW
Severity by source
AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:N/A:N
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
Lifecycle Timeline
3DescriptionGitHub Advisory
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.
AnalysisAI
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. [CVSS 2.0 LOW]
Technical ContextAI
Classified as CWE-200 (Information Exposure). Affects Bigbluebutton. 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.
RemediationAI
A vendor patch is available — apply it immediately. Fixed in version 3.0.20.. Restrict network access to the affected service where possible.
More in Bigbluebutton
View allBigBlueButton through 2.2.28 uses Ghostscript for processing of uploaded EPS documents, and consequently may be subject
BigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the presfilename (lowercase) value ca
The installation procedure in BigBlueButton before 2.2.28 (or earlier) uses ClueCon as the FreeSWITCH password, which al
An issue was discovered in BigBlueButton through 2.2.29. Rated high severity (CVSS 7.5), this vulnerability is remotely
The installation procedure in BigBlueButton before 2.2.28 (or earlier) exposes certain network services to external inte
BigBlueButton before 2.2.27 has an unsafe JODConverter setting in which LibreOffice document conversions can access exte
BigBlueButton before 2.2.5 allows remote attackers to obtain sensitive files via Local File Inclusion. Rated high severi
BigBlueButton versions 3.0.21 and below allow remote denial of service when ClamAV is configured following official docu
In BigBlueButton before 2.2.28 (or earlier), the client-side Mute button only signifies that the server should stop acce
BigBlueButton before 2.3 does not implement LibreOffice sandboxing. Rated medium severity (CVSS 6.5), this vulnerability
BigBlueButton before 2.2.7 allows remote authenticated users to read local files and conduct SSRF attacks via an uploade
In BigBlueButton before 2.2.28 (or earlier), uploaded presentations are sent to clients without a Content-Type header, w
Same weakness CWE-200 – Information Exposure
View allSame technique Information Disclosure
View allShare
External POC / Exploit Code
Leaving vuln.today