CVE-2026-84127

MEDIUMPre-NVD 4.34.3—
EchelonGraph scoreHIGH confidence

Score 4.3 from GitHub Security Advisory published 2026-09-01. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 4.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 4.3Exploit: None knownExposed: 0

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

Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.

CVSS v3
4.3
EG Score
4.3(high)
EG Risk
19(Track)
EG Risk 19/100SSVC: 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
Severity43% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
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

1699444 - (CVE-2026-84127) Tabs opened by extensions are displayed as private when they are not

https://bugzilla.mozilla.org/show_bug.cgi?id=1699444

Vendor Advisories for CVE-2026-84127(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 20× in last 7d / 69× 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. 2026-09-25 00:10 UTCEG score recompute
  2. 2026-09-25 00:10 UTCGHSA enrichment
  3. 2026-09-24 14:04 UTCEPSS rescore
  4. 2026-09-23 23:40 UTCEG score recompute
  5. 2026-09-23 23:40 UTCGHSA enrichment
  6. 2026-09-23 17:54 UTCEPSS rescore
  7. 2026-09-22 23:42 UTCEG score recompute
  8. 2026-09-22 23:42 UTCGHSA enrichment
  9. 2026-09-22 16:01 UTCEPSS rescore
  10. 2026-09-21 23:45 UTCEG score recompute
  11. 2026-09-21 23:45 UTCGHSA enrichment
  12. 2026-09-21 21:09 UTCEPSS rescore
  13. 2026-09-20 23:48 UTCEG score recompute
  14. 2026-09-20 23:48 UTCGHSA enrichment
  15. 2026-09-20 20:16 UTCEPSS rescore
  16. 2026-09-19 23:51 UTCEG score recompute
  17. 2026-09-19 23:51 UTCGHSA enrichment
  18. 2026-09-18 23:55 UTCEG score recompute
  19. 2026-09-18 23:55 UTCGHSA enrichment
  20. 2026-09-18 19:28 UTCEPSS rescore
  21. 2026-09-17 23:58 UTCEG score recompute
  22. 2026-09-17 23:58 UTCGHSA enrichment
  23. 2026-09-17 19:32 UTCEPSS rescore
  24. 2026-09-16 23:35 UTCEG score recompute
  25. 2026-09-16 23:35 UTCGHSA enrichment
Show 44 more
  1. 2026-09-16 14:09 UTCEPSS rescore
  2. 2026-09-16 05:15 UTCEPSS rescore
  3. 2026-09-15 23:38 UTCEG score recompute
  4. 2026-09-15 23:38 UTCGHSA enrichment
  5. 2026-09-15 03:12 UTCEPSS rescore
  6. 2026-09-15 03:12 UTCEPSS rescore
  7. 2026-09-14 23:41 UTCGHSA enrichment
  8. 2026-09-13 23:44 UTCEG score recompute
  9. 2026-09-13 23:44 UTCGHSA enrichment
  10. 2026-09-12 23:48 UTCEG score recompute
  11. 2026-09-12 23:48 UTCGHSA enrichment
  12. 2026-09-11 23:51 UTCEG score recompute
  13. 2026-09-11 23:51 UTCGHSA enrichment
  14. 2026-09-11 14:53 UTCEPSS rescore
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-10 23:54 UTCEG score recompute
  17. 2026-09-10 23:54 UTCGHSA enrichment
  18. 2026-09-09 23:39 UTCGHSA enrichment
  19. 2026-09-08 23:27 UTCEG score recompute
  20. 2026-09-08 23:27 UTCGHSA enrichment
  21. 2026-09-08 22:01 UTCEPSS rescore
  22. 2026-09-07 14:56 UTCEG score recompute
  23. 2026-09-07 14:55 UTCGHSA enrichment
  24. 2026-09-06 13:48 UTCEPSS rescore
  25. 2026-09-06 12:57 UTCEG score recompute
  26. 2026-09-06 12:57 UTCGHSA enrichment
  27. 2026-09-05 15:31 UTCEPSS rescore
  28. 2026-09-05 13:00 UTCEG score recompute
  29. 2026-09-05 13:00 UTCGHSA enrichment
  30. 2026-09-04 13:03 UTCEG score recompute
  31. 2026-09-04 13:03 UTCGHSA enrichment
  32. 2026-09-04 05:07 UTCEPSS rescore
  33. 2026-09-03 13:05 UTCGHSA enrichment
  34. 2026-09-02 21:06 UTCEG score recompute
  35. 2026-09-02 21:06 UTCGHSA enrichment
  36. 2026-09-02 14:12 UTCEPSS rescore
  37. 2026-09-01 21:09 UTCGHSA enrichment
  38. 2026-09-01 15:40 UTCEG score recompute
  39. 2026-09-01 15:40 UTCGHSA enrichment
  40. 2026-09-01 15:13 UTCEG score recompute▲ 4.30
  41. 2026-09-01 15:12 UTCMITRE cvelistV5CVSS v3 → 4.3 · severity → MEDIUM
  42. 2026-09-01 13:35 UTCNVD update
  43. 2026-09-01 12:45 UTCEG score recompute
  44. 2026-09-01 12:41 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-84127?
CVE-2026-84127 is a medium vulnerability published on September 1, 2026. Information disclosure in the WebExtensions component in Firefox for Android. This vulnerability was fixed in Firefox 155.
When was CVE-2026-84127 disclosed?
CVE-2026-84127 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-2026-84127 actively exploited?
CVE-2026-84127 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 84.4% of all scored CVEs.
What is the CVSS score of CVE-2026-84127?
CVE-2026-84127 has a CVSS v3.1 base score of 4.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-84127?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84127, 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-2026-84127

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