CVE-2026-84131

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 due to invalid pointer in the Graphics component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

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
26%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 3, 2026

Advisory Details (5)

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

Security Vulnerabilities fixed in Firefox ESR 153.2 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-85/
generic

Security Vulnerabilities fixed in Firefox ESR 140.15 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-84/
generic

Security Vulnerabilities fixed in Firefox ESR 115.40 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-83/
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=2060008

Vendor Advisories for CVE-2026-84131(1)

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

Affected Packages

(6 across 3 ecosystems)
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.9.1esr-1~deb13u1 (198 versions)140.15.0esr-1~deb12u1—
thunderbird1:102.11.0-1 ... 1:140.9.1esr-1~deb13u1 (227 versions)1:140.15.0esr-1~deb12u1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (74 versions)140.15.0esr-1~deb13u1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (83 versions)1:140.15.0esr-1~deb13u1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (75 versions)140.15.0esr-1—
thunderbird1:128.13.0esr-1 ... 1:153.2.0esr-1 (93 versions)——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 27× in last 7d / 78× 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 07:13 UTCGHSA enrichment
  2. 2026-09-18 19:44 UTCEG score recompute
  3. 2026-09-18 19:44 UTCGHSA enrichment
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 08:15 UTCGHSA enrichment
  6. 2026-09-17 20:46 UTCEG score recompute
  7. 2026-09-17 20:46 UTCGHSA enrichment
  8. 2026-09-17 19:32 UTCEPSS rescore
  9. 2026-09-17 06:12 UTCGHSA enrichment
  10. 2026-09-16 18:42 UTCEG score recompute
  11. 2026-09-16 18:42 UTCGHSA enrichment
  12. 2026-09-16 14:09 UTCEPSS rescore
  13. 2026-09-16 05:55 UTCEG score recompute
  14. 2026-09-16 05:55 UTCGHSA enrichment
  15. 2026-09-16 05:15 UTCEPSS rescore
  16. 2026-09-15 18:26 UTCGHSA enrichment
  17. 2026-09-15 06:45 UTCEG score recompute
  18. 2026-09-15 06:45 UTCGHSA enrichment
  19. 2026-09-15 03:12 UTCEPSS rescore
  20. 2026-09-15 03:12 UTCEPSS rescore
  21. 2026-09-14 19:15 UTCGHSA enrichment
  22. 2026-09-14 07:46 UTCGHSA enrichment
  23. 2026-09-13 20:17 UTCEG score recompute
  24. 2026-09-13 20:17 UTCGHSA enrichment
  25. 2026-09-13 08:48 UTCGHSA enrichment
Show 53 more
  1. 2026-09-12 21:18 UTCEG score recompute
  2. 2026-09-12 21:18 UTCGHSA enrichment
  3. 2026-09-12 09:48 UTCGHSA enrichment
  4. 2026-09-11 22:19 UTCEG score recompute
  5. 2026-09-11 22:19 UTCGHSA enrichment
  6. 2026-09-11 14:53 UTCEPSS rescore
  7. 2026-09-11 14:53 UTCEPSS rescore
  8. 2026-09-11 10:49 UTCEG score recompute
  9. 2026-09-11 10:49 UTCGHSA enrichment
  10. 2026-09-10 23:07 UTCGHSA enrichment
  11. 2026-09-10 11:37 UTCEG score recompute
  12. 2026-09-10 11:37 UTCGHSA enrichment
  13. 2026-09-09 23:39 UTCGHSA enrichment
  14. 2026-09-09 10:56 UTCGHSA enrichment
  15. 2026-09-08 23:27 UTCEG score recompute
  16. 2026-09-08 23:27 UTCGHSA enrichment
  17. 2026-09-08 22:01 UTCEPSS rescore
  18. 2026-09-08 08:04 UTCGHSA enrichment
  19. 2026-09-07 20:34 UTCEG score recompute
  20. 2026-09-07 20:34 UTCGHSA enrichment
  21. 2026-09-07 09:05 UTCGHSA enrichment
  22. 2026-09-06 21:36 UTCEG score recompute
  23. 2026-09-06 21:35 UTCGHSA enrichment
  24. 2026-09-06 13:48 UTCEPSS rescore
  25. 2026-09-06 10:04 UTCGHSA enrichment
  26. 2026-09-05 22:34 UTCEG score recompute
  27. 2026-09-05 22:34 UTCGHSA enrichment
  28. 2026-09-05 15:31 UTCEPSS rescore
  29. 2026-09-05 11:05 UTCGHSA enrichment
  30. 2026-09-04 23:32 UTCEG score recompute
  31. 2026-09-04 23:32 UTCGHSA enrichment
  32. 2026-09-04 12:03 UTCEG score recompute
  33. 2026-09-04 12:03 UTCGHSA enrichment
  34. 2026-09-04 05:07 UTCEPSS rescore
  35. 2026-09-04 00:33 UTCGHSA enrichment
  36. 2026-09-03 13:02 UTCGHSA enrichment
  37. 2026-09-03 03:42 UTCGHSA enrichment
  38. 2026-09-02 16:08 UTCEG score recompute
  39. 2026-09-02 16:08 UTCGHSA enrichment
  40. 2026-09-02 14:12 UTCEPSS rescore
  41. 2026-09-02 04:38 UTCGHSA enrichment
  42. 2026-09-02 04:02 UTCGHSA enrichment
  43. 2026-09-01 22:20 UTCGHSA enrichment
  44. 2026-09-01 21:43 UTCGHSA enrichment
  45. 2026-09-01 21:09 UTCEG score recompute
  46. 2026-09-01 21:09 UTCGHSA enrichment
  47. 2026-09-01 17:22 UTCGHSA enrichment
  48. 2026-09-01 16:51 UTCEG score recompute▲ 8.80
  49. 2026-09-01 16:51 UTCGHSA enrichment
  50. 2026-09-01 16:48 UTCMITRE cvelistV5CVSS v3 → 8.8 · severity → HIGH
  51. 2026-09-01 13:35 UTCNVD update
  52. 2026-09-01 12:45 UTCEG score recompute
  53. 2026-09-01 12:41 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84131?
CVE-2026-84131 is a high vulnerability published on September 1, 2026. Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
When was CVE-2026-84131 disclosed?
CVE-2026-84131 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-2026-84131 actively exploited?
CVE-2026-84131 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 73.8% of all scored CVEs.
What is the CVSS score of CVE-2026-84131?
CVE-2026-84131 has a CVSS v3.1 base score of 8.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-84131?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84131, 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

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