CVE-2026-84128

HIGHPre-NVD 8.88.8—
EchelonGraph scoreHIGH confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-09-01. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.8Exploit: None knownExposed: 0

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

Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.

CVSS v3
8.8
EG Score
8.8(high)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
14%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 3, 2026

Advisory Details (2)

Auto-updated Sep 1, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Firefox 155 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-82/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2044280

Vendor Advisories for CVE-2026-84128(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 28× in last 7d / 80× 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. 2026-09-19 19:53 UTCEG score recompute
  2. 2026-09-19 19:53 UTCGHSA enrichment
  3. 2026-09-19 08:44 UTCGHSA enrichment
  4. 2026-09-18 21:25 UTCEG score recompute
  5. 2026-09-18 21:25 UTCGHSA enrichment
  6. 2026-09-18 19:28 UTCEPSS rescore
  7. 2026-09-18 09:16 UTCGHSA enrichment
  8. 2026-09-17 22:06 UTCEG score recompute
  9. 2026-09-17 22:06 UTCGHSA enrichment
  10. 2026-09-17 19:32 UTCEPSS rescore
  11. 2026-09-17 10:56 UTCGHSA enrichment
  12. 2026-09-16 23:47 UTCEG score recompute
  13. 2026-09-16 23:47 UTCGHSA enrichment
  14. 2026-09-16 14:09 UTCEPSS rescore
  15. 2026-09-16 12:38 UTCEG score recompute
  16. 2026-09-16 12:38 UTCGHSA enrichment
  17. 2026-09-16 05:15 UTCEPSS rescore
  18. 2026-09-16 01:29 UTCGHSA enrichment
  19. 2026-09-15 14:20 UTCEG score recompute
  20. 2026-09-15 14:20 UTCGHSA enrichment
  21. 2026-09-15 03:12 UTCEPSS rescore
  22. 2026-09-15 03:12 UTCEPSS rescore
  23. 2026-09-15 03:10 UTCGHSA enrichment
  24. 2026-09-14 16:01 UTCGHSA enrichment
  25. 2026-09-14 04:51 UTCGHSA enrichment
Show 55 more
  1. 2026-09-13 17:42 UTCEG score recompute
  2. 2026-09-13 17:42 UTCGHSA enrichment
  3. 2026-09-13 06:32 UTCGHSA enrichment
  4. 2026-09-12 19:23 UTCEG score recompute
  5. 2026-09-12 19:23 UTCGHSA enrichment
  6. 2026-09-12 08:14 UTCGHSA enrichment
  7. 2026-09-11 21:04 UTCEG score recompute
  8. 2026-09-11 21:04 UTCGHSA enrichment
  9. 2026-09-11 14:53 UTCEPSS rescore
  10. 2026-09-11 14:53 UTCEPSS rescore
  11. 2026-09-11 09:55 UTCEG score recompute
  12. 2026-09-11 09:55 UTCGHSA enrichment
  13. 2026-09-10 22:46 UTCGHSA enrichment
  14. 2026-09-10 11:37 UTCEG score recompute
  15. 2026-09-10 11:37 UTCGHSA enrichment
  16. 2026-09-09 23:39 UTCGHSA enrichment
  17. 2026-09-09 10:36 UTCGHSA enrichment
  18. 2026-09-08 23:27 UTCEG score recompute
  19. 2026-09-08 23:27 UTCGHSA enrichment
  20. 2026-09-08 22:01 UTCEPSS rescore
  21. 2026-09-08 05:39 UTCGHSA enrichment
  22. 2026-09-07 18:27 UTCEG score recompute
  23. 2026-09-07 18:27 UTCGHSA enrichment
  24. 2026-09-07 07:18 UTCGHSA enrichment
  25. 2026-09-06 20:08 UTCEG score recompute
  26. 2026-09-06 20:08 UTCGHSA enrichment
  27. 2026-09-06 13:48 UTCEPSS rescore
  28. 2026-09-06 08:56 UTCGHSA enrichment
  29. 2026-09-05 21:47 UTCEG score recompute
  30. 2026-09-05 21:47 UTCGHSA enrichment
  31. 2026-09-05 15:31 UTCEPSS rescore
  32. 2026-09-05 10:37 UTCGHSA enrichment
  33. 2026-09-04 23:27 UTCEG score recompute
  34. 2026-09-04 23:27 UTCGHSA enrichment
  35. 2026-09-04 11:23 UTCEG score recompute
  36. 2026-09-04 11:23 UTCGHSA enrichment
  37. 2026-09-04 05:07 UTCEPSS rescore
  38. 2026-09-04 00:13 UTCGHSA enrichment
  39. 2026-09-03 12:59 UTCGHSA enrichment
  40. 2026-09-03 03:04 UTCGHSA enrichment
  41. 2026-09-02 15:54 UTCEG score recompute
  42. 2026-09-02 15:53 UTCGHSA enrichment
  43. 2026-09-02 14:12 UTCEPSS rescore
  44. 2026-09-02 04:38 UTCGHSA enrichment
  45. 2026-09-02 04:02 UTCGHSA enrichment
  46. 2026-09-01 22:19 UTCGHSA enrichment
  47. 2026-09-01 21:43 UTCGHSA enrichment
  48. 2026-09-01 21:09 UTCGHSA enrichment
  49. 2026-09-01 15:40 UTCEG score recompute
  50. 2026-09-01 15:40 UTCGHSA enrichment
  51. 2026-09-01 14:27 UTCEG score recompute▲ 8.80
  52. 2026-09-01 14:23 UTCMITRE cvelistV5CVSS v3 → 8.8 · severity → HIGH
  53. 2026-09-01 13:35 UTCNVD update
  54. 2026-09-01 12:45 UTCEG score recompute
  55. 2026-09-01 12:41 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-84128?
CVE-2026-84128 is a high vulnerability published on September 1, 2026. Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
When was CVE-2026-84128 disclosed?
CVE-2026-84128 was first published in the National Vulnerability Database on September 1, 2026, with the most recent update on September 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84128 actively exploited?
CVE-2026-84128 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 85.5% of all scored CVEs.
What is the CVSS score of CVE-2026-84128?
CVE-2026-84128 has a CVSS v3.1 base score of 8.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-84128?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84128, 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-2026-84128

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