What is CVE-2026-46353?

CVE-2026-46353 is a high-severity vulnerability in Bigbluebutton, classified under Improper Access Control. CVSS score: 8.1/10. Published 2026-07-16.

How severe is CVE-2026-46353?

High severity. CVSS v3 base score is 8.1 out of 10.

Vulnerability in Bigbluebutton

CVE-2026-46353

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.

EPSS: 0.005 (39.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.

Affected products

Bigbluebutton — versions < 3.0.21

Weakness classification (CWE)

CWE-284 — Improper Access Control

References

security-advisories@github.com (x_refsource_CONFIRM)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-46353?: CVE-2026-46353 is a high-severity vulnerability in Bigbluebutton, classified under Improper Access Control. CVSS score: 8.1/10. Published 2026-07-16.
How severe is CVE-2026-46353?: High severity. CVSS v3 base score is 8.1 out of 10.