Vulnerabilidades de Bigbluebutton

CVE-2026-46404 Média · 6.8 CWE-918 16/07/2026

BigBlueButton: Presentation URL Security Hardening

BigBlueButton is an open-source virtual classroom. Prior to 3.0.23, the presentation URL validation did not properly restrict access to site local and link local addresses. The redirect following logic now pins resolved IPs. This issue is fixed in version 3.0.23.

CVE-2026-46353 Alta · 8.1 CWE-284 16/07/2026

BigBlueButton API checksum bypass via presentationUploadExternalUrl

BigBlueButton is an open-source virtual classroom. Prior to 3.0.21, bbb-web checksum validation could be bypassed when a presentationUploadExternalUrl parameter was supplied to API request handling in CreateMeeting.java and ValidationService.java, allowing a user to send valid requests to some endpoints without a checksum. This issue is fixed in version 3.0.21.

CVE-2026-46351 Alta · 8.1 CWE-330 16/07/2026

BigBlueButton: Insecure Randomness allows to guess user's conference session token and impersonate them

BigBlueButton is an open-source virtual classroom. Prior to 3.0.21, bbb-web generated conference sessionToken values with insufficiently secure randomness in bbb-common-web/src/main/java/org/bigbluebutton/api/Util.java and bigbluebutton-web/grails-app/controllers/org/bigbluebutton/web/controllers/ApiController.groovy, allowing a session user to predict other users' conference session tokens and impersonate them. This issue is fixed in version 3.0.21.

CVE-2026-27737 Média · 6.5 CWE-79 18/05/2026

BigBlueButton has Stored XSS in bbb-playback replay

BigBlueButton is an open-source virtual classroom. In versions prior to 3.0.19, the recording playback (presentation format) was not sanitizing user's input in public chat. This allowed for a malicious actor to craft and carry out a targeted XSS attack, activated on anyone replaying the recording. This issue has been fixed 3.0.19.

CVE-2026-41127 Média · 6.5 CWE-639 21/04/2026

BigBlueButton's missing authorization allows viewer to inject/overwrite captions

BigBlueButton is an open-source virtual classroom. Versions prior to 3.0.24 have a missing authorization that allows viewers to inject/overwrite captions Version 3.0.24 tightened the permissions on who is able to submit captions. No known workarounds are available.

CVE-2026-41126 Média · 4.3 CWE-601 21/04/2026

BigBlueButton has Open Redirect through bigbluebutton/api/join via get-parameter "logoutURL"

BigBlueButton is an open-source virtual classroom. Versions prior to 3.0.24 have an Open Redirect through bigbluebutton/api/join via get-parameter "logoutURL." Version 3.0.24 has adjusted the handling of requests with incorrect checksum so that the default logoutURL is used. No known workarounds are available.

CVE-2026-27736 Média · 6.1 CWE-601 25/02/2026

BigBlueButton has Open Redirect vulnerability in ApiController

BigBlueButton is an open-source virtual classroom. In versions on the 3.x branch prior to 3.0.20, the string received with errorRedirectUrl lacks validation, using it directly in the respondWithRedirect function leads to an Open Redirect vulnerability. BigBlueButton 3.0.20 patches the issue. No known workarounds are available.

CVE-2026-27467 Baixa · 2.4 CWE-200 21/02/2026

BigBlueButton: Audio from participants to the server initially unmuted

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.

CVE-2026-27466 Alta · 8.2 CWE-668 21/02/2026

BigBlueButton: Exposed ClamAV port enables Denial of Service

BigBlueButton is an open-source virtual classroom. In versions 3.0.21 and below, the official documentation for "Server Customization" on Support for ClamAV as presentation file scanner contains instructions that leave a BBB server vulnerable for Denial of Service. The flawed command exposes both ports (3310 and 7357) to the internet. A remote attacker can use this to send complex or large documents to clamd and waste server resources, or shutdown the clamd process. The clamd documentation explicitly warns about exposing this port. Enabling ufw (ubuntu firewall) during install does not help, because Docker routes container traffic through the nat table, which is not managed or restricted by ufw. Rules installed by ufw in the filter table have no effect on docker traffic. In addition, the provided example also mounts /var/bigbluebutton with write permissions into the container, which should not be required. Future vulnerabilities in clamd may allow attackers to manipulate files in that folder. Users are unaffected unless they have opted in to follow the extra instructions from BigBlueButton's documentation. This issue has been fixed in version 3.0.22.