CVE-2026-84641

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-02. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — Patch released this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID response. Heap contents can ultimately be persisted to prefs.js. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
35%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 3, 2026

Advisory Details (4)

Auto-updated Sep 2, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 153.2 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-88/
generic

Security Vulnerabilities fixed in Thunderbird 140.15 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-87/
generic

Security Vulnerabilities fixed in Thunderbird 155 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-86/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2057805

Vendor Advisories for CVE-2026-84641(1)

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

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatthunderbird-0:140.16.0-1.el9_82026-09-24redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
thunderbird1:102.11.0-1 ... 1:140.9.1esr-1~deb13u1 (227 versions)1:140.15.0esr-1~deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (83 versions)1:140.15.0esr-1~deb13u1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
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.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 29× in last 7d / 94× 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 08:33 UTCVendor advisory
  2. 2026-09-25 08:33 UTCGHSA enrichment
  3. 2026-09-24 20:18 UTCEG score recompute
  4. 2026-09-24 20:18 UTCVendor advisory
  5. 2026-09-24 20:18 UTCGHSA enrichment
  6. 2026-09-24 14:04 UTCEPSS rescore
  7. 2026-09-24 08:04 UTCGHSA enrichment
  8. 2026-09-23 19:49 UTCEG score recompute
  9. 2026-09-23 19:49 UTCGHSA enrichment
  10. 2026-09-23 17:54 UTCEPSS rescore
  11. 2026-09-23 06:57 UTCGHSA enrichment
  12. 2026-09-22 18:42 UTCEG score recompute
  13. 2026-09-22 18:42 UTCGHSA enrichment
  14. 2026-09-22 16:01 UTCEPSS rescore
  15. 2026-09-22 06:27 UTCEG score recompute
  16. 2026-09-22 06:26 UTCGHSA enrichment
  17. 2026-09-21 21:09 UTCEPSS rescore
  18. 2026-09-21 18:12 UTCGHSA enrichment
  19. 2026-09-21 05:56 UTCEG score recompute
  20. 2026-09-21 05:56 UTCGHSA enrichment
  21. 2026-09-20 20:16 UTCEPSS rescore
  22. 2026-09-20 17:41 UTCGHSA enrichment
  23. 2026-09-20 05:22 UTCGHSA enrichment
  24. 2026-09-19 17:07 UTCEG score recompute
  25. 2026-09-19 17:07 UTCGHSA enrichment
Show 69 more
  1. 2026-09-19 04:52 UTCEG score recompute
  2. 2026-09-19 04:52 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 16:37 UTCGHSA enrichment
  5. 2026-09-18 04:22 UTCEG score recompute
  6. 2026-09-18 04:22 UTCGHSA enrichment
  7. 2026-09-17 19:32 UTCEPSS rescore
  8. 2026-09-17 16:07 UTCGHSA enrichment
  9. 2026-09-17 03:52 UTCGHSA enrichment
  10. 2026-09-16 15:37 UTCEG score recompute
  11. 2026-09-16 15:37 UTCGHSA enrichment
  12. 2026-09-16 14:09 UTCEPSS rescore
  13. 2026-09-16 05:15 UTCEPSS rescore
  14. 2026-09-16 03:06 UTCGHSA enrichment
  15. 2026-09-15 14:51 UTCEG score recompute
  16. 2026-09-15 14:51 UTCGHSA enrichment
  17. 2026-09-15 03:12 UTCEPSS rescore
  18. 2026-09-15 03:12 UTCEPSS rescore
  19. 2026-09-15 02:36 UTCGHSA enrichment
  20. 2026-09-14 14:21 UTCGHSA enrichment
  21. 2026-09-14 02:06 UTCEG score recompute
  22. 2026-09-14 02:06 UTCGHSA enrichment
  23. 2026-09-13 13:52 UTCGHSA enrichment
  24. 2026-09-13 01:38 UTCEG score recompute
  25. 2026-09-13 01:38 UTCGHSA enrichment
  26. 2026-09-12 13:23 UTCGHSA enrichment
  27. 2026-09-12 01:08 UTCEG score recompute
  28. 2026-09-12 01:08 UTCGHSA enrichment
  29. 2026-09-11 14:53 UTCEPSS rescore
  30. 2026-09-11 14:53 UTCEPSS rescore
  31. 2026-09-11 12:54 UTCEG score recompute
  32. 2026-09-11 12:54 UTCGHSA enrichment
  33. 2026-09-11 00:18 UTCGHSA enrichment
  34. 2026-09-10 12:04 UTCEG score recompute
  35. 2026-09-10 12:04 UTCGHSA enrichment
  36. 2026-09-09 23:48 UTCGHSA enrichment
  37. 2026-09-09 11:33 UTCGHSA enrichment
  38. 2026-09-08 23:18 UTCEG score recompute
  39. 2026-09-08 23:18 UTCGHSA enrichment
  40. 2026-09-08 22:01 UTCEPSS rescore
  41. 2026-09-08 10:01 UTCGHSA enrichment
  42. 2026-09-07 21:29 UTCEG score recompute
  43. 2026-09-07 21:29 UTCGHSA enrichment
  44. 2026-09-07 09:14 UTCGHSA enrichment
  45. 2026-09-06 20:54 UTCEG score recompute
  46. 2026-09-06 20:54 UTCGHSA enrichment
  47. 2026-09-06 13:48 UTCEPSS rescore
  48. 2026-09-06 08:39 UTCGHSA enrichment
  49. 2026-09-05 20:24 UTCEG score recompute
  50. 2026-09-05 20:24 UTCGHSA enrichment
  51. 2026-09-05 15:31 UTCEPSS rescore
  52. 2026-09-05 08:10 UTCGHSA enrichment
  53. 2026-09-04 19:55 UTCEG score recompute
  54. 2026-09-04 19:55 UTCGHSA enrichment
  55. 2026-09-04 07:37 UTCEG score recompute
  56. 2026-09-04 07:36 UTCGHSA enrichment
  57. 2026-09-04 05:07 UTCEPSS rescore
  58. 2026-09-03 19:20 UTCGHSA enrichment
  59. 2026-09-03 18:05 UTCGHSA enrichment
  60. 2026-09-03 07:53 UTCEG score recompute
  61. 2026-09-03 07:53 UTCGHSA enrichment
  62. 2026-09-02 19:32 UTCGHSA enrichment
  63. 2026-09-02 18:57 UTCEG score recompute▲ 7.50
  64. 2026-09-02 18:57 UTCGHSA enrichment
  65. 2026-09-02 18:55 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  66. 2026-09-02 14:12 UTCEPSS rescore
  67. 2026-09-01 22:18 UTCNVD update
  68. 2026-09-01 21:43 UTCEG score recompute
  69. 2026-09-01 21:42 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-84641?
CVE-2026-84641 is a high vulnerability published on September 1, 2026. A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID response. Heap contents can ultimately be persisted to prefs.js. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
When was CVE-2026-84641 disclosed?
CVE-2026-84641 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-2026-84641 actively exploited?
CVE-2026-84641 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 64.6% of all scored CVEs.
What is the CVSS score of CVE-2026-84641?
CVE-2026-84641 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-84641?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84641, 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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