CVE-2026-27467

BigBlueButton: Audio from participants to the server initially unmuted

LOW
2.4
CVSS Score
Published: February 21, 2026 at 07:18 AM UTC
Updated: June 17, 2026 at 10:27 AM UTC
1 product affected across 1 vendorBigbluebutton

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Severity
LOW2.4
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.0.20
Affected range stops below 3.0.20, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
HIGH
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-200

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