CVE-2026-27467 BigBlueButton: Audio from participants to the server initially unmuted
Malicious server operators can access audio data from muted participants during initial session join in BigBlueButton.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-27467?
CVE-2026-27467 is a low-severity vulnerability in bigbluebutton, published on 21 Feb 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-200
Which versions are affected by CVE-2026-27467?
It affects 1 product.
Products include Bigbluebutton Bigbluebutton.
How do I fix CVE-2026-27467?
No fix has been published for CVE-2026-27467 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-27467 being exploited?
There is no known exploitation of CVE-2026-27467 in the wild and no public exploit code.
Other vulnerabilities in bigbluebutton
Sources
Also known as GHSA-6gj9-5rhm-68j8.