CVE-2026-46353CWE-284

BigBlueButton API checksum bypass via presentationUploadExternalUrl

High · published July 16, 2026

CVSS v3.1
8.1
EPSS
0%
Percentile
40.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00476 · 40.2th percentile
Weakness
CWE-284 · Improper Access Control
Published
2026-07-16T18:06Z
EPSS history
Timeline
  • 16 JUL 18:06Z
    BigBlueButton API checksum bypass via presentationUploadExternalUrl
    cvelistv5