CVE-2026-46353

BigBlueButton API checksum bypass via presentationUploadExternalUrl

Published Jul 16, 2026 CVSS 3.1 · 8.1 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Bigbluebutton
Bigbluebutton bigbluebutton
Vendors & Products Bigbluebutton
Bigbluebutton bigbluebutton
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title BigBlueButton API checksum bypass via presentationUploadExternalUrl
Weaknesses CWE-284
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jul 16, 2026, 6:41 PM
Reserved
May 13, 2026, 6:37 PM
Status
Deferred
Published
Jul 16, 2026, 7:16 PM
Modified
Jul 17, 2026, 6:33 PM