Audio disclosure via unenforced initial mute state
Published Feb 21, 2026 · Updated Feb 21, 2026
Information exposure in BigBlueButton 3.0.19 and earlier allows attackers controlling the server to capture muted participant audio during initial join. AudioManager.onAudioJoining fails to enforce the initial muted state, leaving the local MediaStreamTrack enabled while it transmits audio to the server. The server discards the stream for other participants, but a malicious server operator can access it only until the participant first unmutes.
Summary
What happened
Information exposure in BigBlueButton 3.0.19 and earlier allows attackers controlling the server to capture muted participant audio during initial join. AudioManager.onAudioJoining fails to enforce the initial muted state, leaving the local MediaStreamTrack enabled while it transmits audio to the server. The server discards the stream for other participants, but a malicious server operator can access it only until the participant first unmutes.
The record
- CVE
- CVE-2026-27467
- Published
- Feb 21, 2026
- Updated
- Feb 21, 2026
- Vendor
- BigBlueButton Inc.
- Product
- BigBlueButton
- Classifications
- CWE-200, T1123
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Feb 21, 2026CVE publishedPublication date reported by the CVE source.
- Feb 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=< 3.0.20
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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