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Vulnerability record · CVE-2026-27467 · published 21 February 2026

CVE-2026-27467: Bigbluebutton information exposure vulnerability

Bigbluebutton · 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.

2.4 CVSS 3.1 Low EPSS 0.28% · top 81.2% CWE-200 · Information exposure
2.4CVSS 3.1 base score
0.28%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

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:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:N/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2020-27602Bigbluebutton injection vulnerabilityBigBlueButton before 2.2.7 does not have a protection mechanism for separator injection in meetingId, userId, and authToken.EPSS 1.4%9.8CVE-2020-27605Bigbluebutton vulnerabilityBigBlueButton through 2.2.28 uses Ghostscript for processing of uploaded EPS documents, and consequently may be subject to attacks related to a "schw…EPSS 1.2%9.8CVE-2020-12443Bigbluebutton path traversal vulnerabilityBigBlueButton before 2.2.6 allows remote attackers to read arbitrary files because the presfilename (lowercase) value can be a .pdf filename while th…EPSS 3.7%8.8CVE-2023-42803Bigbluebutton unrestricted file upload vulnerabilityBigBlueButton is an open-source virtual classroom. BigBlueButton prior to version 2.6.0-beta.2 is vulnerable to unrestricted file upload, where the i…EPSS 0.54%8.4CVE-2020-27613Bigbluebutton cleartext storage of sensitive data vulnerabilityThe installation procedure in BigBlueButton before 2.2.28 (or earlier) uses ClueCon as the FreeSWITCH password, which allows local users to achieve u…EPSS 0.27%8.2CVE-2026-27466Bigbluebutton exposure of resource to wrong sphere vulnerabilityBigBlueButton is an open-source virtual classroom. In versions 3.0.21 and below, the official documentation for "Server Customization" on Support for…EPSS 0.58%7.5CVE-2025-61601Bigbluebutton vulnerabilityBigBlueButton is an open-source virtual classroom. A Denial of Service (DoS) vulnerability in versions prior to 3.0.13 allows any authenticated user …EPSS 0.47%7.5CVE-2025-61602Bigbluebutton vulnerabilityBigBlueButton is an open-source virtual classroom. A denial-of-service (DoS) vulnerability in versions prior to 3.0.13 allows any authenticated user …EPSS 0.39%

Source: NIST National Vulnerability Database (record CVE-2026-27467), CISA KEV, FIRST EPSS (scores of 2026-09-30). This page is refreshed as NVD updates the record.