CVE-2026-46353

8.1 highEPSS 0.5%

High (8.1). EPSS 0.5% chance of exploitation in the next 30 days.

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.

Severity

CVSS 3.1

8.1 high

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

EPSS: 0.5% chance of exploitation in the next 30 days; higher than 41% of CVEs (scores of 2026-10-31)
CWE: CWE-284
Published: 2026-07-16
Modified: 2026-07-17
Record from: the NVD, synced 2026-10-19

References

https://github.com/bigbluebutton/bigbluebutton/commit/36fd1b407488a0c56ce620b91184d5a8aea68b3d
https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.21
https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-43hc-5g2m-cqff

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