CVE-2026-46353

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 82% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
8.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
37(Track)
EG Risk 37/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity81% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
18%
KEV
Not listed

Published

July 16, 2026

Last Modified

July 17, 2026

Advisory Details (3)

Auto-updated Jul 16, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

BigBlueButton API checksum bypass via presentationUploadExternalUrl · Advisory · bigbluebutton/bigbluebutton · GitHub

https://github.com/bigbluebutton/bigbluebutton/security/advisories/GHSA-43hc-5g2m-cqff
github_release Patch Available

v3.0.21

Patch available: bigbluebutton/bigbluebutton v3.0.21

https://github.com/bigbluebutton/bigbluebutton/releases/tag/v3.0.21
github_commit

commit 36fd1b407488 (bigbluebutton/bigbluebutton)

Fix landed in bigbluebutton/bigbluebutton commit 36fd1b407488 — awaiting tagged release

https://github.com/bigbluebutton/bigbluebutton/commit/36fd1b407488a0c56ce620b91184d5a8aea68b3d

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 14× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-31 00:59 UTCEG score recompute
  2. 2026-07-30 16:28 UTCEPSS rescore
  3. 2026-07-30 12:49 UTCEG score recompute
  4. 2026-07-30 01:30 UTCEPSS rescore
  5. 2026-07-29 00:18 UTCEG score recompute
  6. 2026-07-28 15:36 UTCEPSS rescore
  7. 2026-07-27 23:55 UTCEG score recompute
  8. 2026-07-27 14:13 UTCEPSS rescore
  9. 2026-07-26 23:35 UTCEG score recompute
  10. 2026-07-26 14:54 UTCEPSS rescore
  11. 2026-07-26 14:54 UTCEPSS rescore
  12. 2026-07-26 11:25 UTCEG score recompute
  13. 2026-07-25 14:18 UTCEPSS rescore
  14. 2026-07-24 14:17 UTCEPSS rescore
  15. 2026-07-23 14:18 UTCEPSS rescore
  16. 2026-07-23 03:17 UTCEG score recompute
  17. 2026-07-22 14:08 UTCEPSS rescore
  18. 2026-07-20 17:08 UTCEPSS rescore
  19. 2026-07-19 14:31 UTCEPSS rescore
  20. 2026-07-19 02:34 UTCEG score recompute
  21. 2026-07-19 02:29 UTCEPSS rescore
  22. 2026-07-18 10:04 UTCEPSS rescore
  23. 2026-07-16 18:20 UTCEG score recompute
  24. 2026-07-16 18:18 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-46353?
CVE-2026-46353 is a high vulnerability published on July 16, 2026. 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…
When was CVE-2026-46353 disclosed?
CVE-2026-46353 was first published in the National Vulnerability Database on July 16, 2026, with the most recent update on July 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-46353 actively exploited?
CVE-2026-46353 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 81.6% of all scored CVEs.
What is the CVSS score of CVE-2026-46353?
CVE-2026-46353 has a CVSS v3 base score of 8.1 (NVD).
How do I remediate CVE-2026-46353?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-46353, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-46353

Explore →

Is Your Infrastructure Affected by CVE-2026-46353?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs