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: 0.5%, top 61% 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
40%
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 8× in last 7d / 44× 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. 2026-09-11 14:53 UTCEPSS rescore
  2. 2026-09-11 09:37 UTCEPSS rescore
  3. 2026-09-10 09:34 UTCEPSS rescore
  4. 2026-09-08 22:00 UTCEPSS rescore
  5. 2026-09-08 00:27 UTCEG score recompute
  6. 2026-09-07 16:01 UTCEPSS rescore
  7. 2026-09-06 13:47 UTCEPSS rescore
  8. 2026-09-05 20:37 UTCEG score recompute
  9. 2026-09-04 05:06 UTCEPSS rescore
  10. 2026-09-02 14:12 UTCEPSS rescore
  11. 2026-09-01 13:54 UTCEPSS rescore
  12. 2026-08-31 04:29 UTCEG score recompute
  13. 2026-08-30 19:17 UTCEPSS rescore
  14. 2026-08-30 03:32 UTCEG score recompute
  15. 2026-08-30 01:22 UTCEPSS rescore
  16. 2026-08-28 21:41 UTCEPSS rescore
  17. 2026-08-27 15:17 UTCEG score recompute
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-27 02:28 UTCEG score recompute
  20. 2026-08-26 14:46 UTCEPSS rescore
  21. 2026-08-25 13:55 UTCEG score recompute
  22. 2026-08-25 13:49 UTCEPSS rescore
  23. 2026-08-25 01:46 UTCEG score recompute
  24. 2026-08-24 13:37 UTCEG score recompute
  25. 2026-08-23 01:07 UTCEG score recompute
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  1. 2026-08-23 00:19 UTCEPSS rescore
  2. 2026-08-22 00:47 UTCEG score recompute
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-21 00:24 UTCEG score recompute
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 23:53 UTCEG score recompute
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-18 21:53 UTCEG score recompute
  9. 2026-08-18 13:48 UTCEPSS rescore
  10. 2026-08-17 21:18 UTCEG score recompute
  11. 2026-08-17 13:47 UTCEPSS rescore
  12. 2026-08-16 19:50 UTCEG score recompute
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 07:40 UTCEG score recompute
  15. 2026-08-16 02:14 UTCEPSS rescore
  16. 2026-08-15 07:22 UTCEG score recompute
  17. 2026-08-15 01:30 UTCEPSS rescore
  18. 2026-08-14 05:54 UTCEG score recompute
  19. 2026-08-13 22:00 UTCEPSS rescore
  20. 2026-08-12 17:20 UTCEG score recompute
  21. 2026-08-12 13:51 UTCEPSS rescore
  22. 2026-08-11 17:02 UTCEG score recompute
  23. 2026-08-11 04:53 UTCEG score recompute
  24. 2026-08-11 00:00 UTCEPSS rescore
  25. 2026-08-09 16:13 UTCEG score recompute
  26. 2026-08-09 13:46 UTCEPSS rescore
  27. 2026-08-09 04:04 UTCEG score recompute
  28. 2026-08-08 16:37 UTCEPSS rescore
  29. 2026-08-08 03:45 UTCEG score recompute
  30. 2026-08-06 15:18 UTCEG score recompute
  31. 2026-08-06 13:47 UTCEPSS rescore
  32. 2026-08-06 03:08 UTCEG score recompute
  33. 2026-08-05 19:17 UTCEPSS rescore
  34. 2026-08-05 02:34 UTCEG score recompute
  35. 2026-08-04 15:10 UTCEPSS rescore
  36. 2026-08-04 14:24 UTCEG score recompute
  37. 2026-08-04 10:39 UTCEPSS rescore
  38. 2026-08-03 14:06 UTCEG score recompute
  39. 2026-08-03 10:36 UTCEPSS rescore
  40. 2026-08-02 13:46 UTCEG score recompute
  41. 2026-08-02 02:27 UTCEPSS rescore
  42. 2026-08-01 13:28 UTCEG score recompute
  43. 2026-08-01 04:16 UTCEPSS rescore
  44. 2026-07-31 00:59 UTCEG score recompute
  45. 2026-07-30 16:28 UTCEPSS rescore
  46. 2026-07-30 12:49 UTCEG score recompute
  47. 2026-07-30 01:30 UTCEPSS rescore
  48. 2026-07-29 00:18 UTCEG score recompute
  49. 2026-07-28 15:36 UTCEPSS rescore
  50. 2026-07-27 23:55 UTCEG score recompute
  51. 2026-07-27 14:13 UTCEPSS rescore
  52. 2026-07-26 23:35 UTCEG score recompute
  53. 2026-07-26 14:54 UTCEPSS rescore
  54. 2026-07-26 14:54 UTCEPSS rescore
  55. 2026-07-26 11:25 UTCEG score recompute
  56. 2026-07-25 14:18 UTCEPSS rescore
  57. 2026-07-24 14:17 UTCEPSS rescore
  58. 2026-07-23 14:18 UTCEPSS rescore
  59. 2026-07-23 03:17 UTCEG score recompute
  60. 2026-07-22 14:08 UTCEPSS rescore
  61. 2026-07-20 17:08 UTCEPSS rescore
  62. 2026-07-19 14:31 UTCEPSS rescore
  63. 2026-07-19 02:34 UTCEG score recompute
  64. 2026-07-19 02:29 UTCEPSS rescore
  65. 2026-07-18 10:04 UTCEPSS rescore
  66. 2026-07-16 18:20 UTCEG score recompute
  67. 2026-07-16 18:18 UTCMITRE cvelistV5first tracked

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 60.3% 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.

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