CVE-2026-2786

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-02-24. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
25%
KEV
Not listed

Published

February 24, 2026

Last Modified

June 17, 2026

Advisory Details (5)

Auto-updated Sep 14, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 140.8 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-17/
generic

Security Vulnerabilities fixed in Thunderbird 148 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-16/
generic

Security Vulnerabilities fixed in Firefox ESR 140.8 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-15/
generic

Security Vulnerabilities fixed in Firefox 148 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-13/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2013612

Vendor Advisories for CVE-2026-2786(20)

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

Patch Availability(25)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatthunderbird-0:140.8.0-1.el8_22026-03-12redhat
redhatthunderbird-0:140.8.0-2.el10_02026-03-11redhat
redhatfirefox-0:140.8.0-2.el9_22026-03-10redhat
redhatthunderbird-0:140.8.0-1.el8_82026-03-09redhat
redhatthunderbird-0:140.8.0-1.el9_42026-03-09redhat
redhatfirefox-0:140.8.0-2.el10_02026-03-09redhat
redhatfirefox-0:140.8.0-2.el7_92026-03-09redhat
redhatthunderbird-0:140.8.0-1.el8_62026-03-09redhat
redhatthunderbird-0:140.8.0-1.el9_02026-03-09redhat
redhatthunderbird-0:140.8.0-1.el9_22026-03-09redhat
redhatthunderbird-0:140.8.0-2.el8_42026-03-09redhat
redhatthunderbird-0:140.8.0-1.el9_62026-03-09redhat
redhatfirefox-0:140.8.0-2.el8_82026-03-02redhat
redhatfirefox-0:140.8.0-2.el9_62026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_62026-03-02redhat
redhatfirefox-0:140.8.0-2.el9_02026-03-02redhat
redhatfirefox-0:140.8.0-2.el9_42026-03-02redhat
redhatthunderbird-0:140.8.0-2.el10_12026-03-02redhat
redhatthunderbird-0:140.8.0-1.el9_72026-03-02redhat
redhatthunderbird-0:140.8.0-1.el8_102026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_22026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_42026-03-02redhat
redhatfirefox-0:140.8.0-2.el8_102026-02-25redhat
redhatfirefox-0:140.8.0-2.el9_72026-02-25redhat
redhatfirefox-0:140.8.0-2.el10_12026-02-25redhat

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

(8 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.1.0esr-1 ... 91.9.1esr-1~deb9u1 (251 versions)140.8.0esr-1~deb11u1—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (302 versions)1:140.8.0esr-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.8.0esr-1~deb11u1 (158 versions)140.8.0esr-1~deb12u1—
thunderbird1:102.11.0-1 ... 1:140.8.0esr-1~deb11u1 (187 versions)1:140.8.0esr-1~deb12u1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.8.0esr-1~deb12u1 (34 versions)140.8.0esr-1~deb13u1—
thunderbird1:128.13.0esr-1 ... 1:140.8.0esr-1~deb12u1 (43 versions)1:140.8.0esr-1~deb13u1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.8.0esr-1~deb13u1 (35 versions)140.8.0esr-1—
thunderbird1:128.13.0esr-1 ... 1:140.8.0esr-1~deb13u1 (44 versions)1:140.8.0esr-1—

Weakness Classification(1)

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

Additional Vendor Advisories

(5)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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.

Showing the most recent 100 of 272 total refreshes for this CVE.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-12 15:01 UTCEPSS rescore
  8. 2026-09-11 14:52 UTCEPSS rescore
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-08 22:00 UTCEPSS rescore
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 14:11 UTCEPSS rescore
  16. 2026-09-01 13:53 UTCEPSS rescore
  17. 2026-09-01 04:39 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-09-01 01:04 UTCOSV refresh
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:49 UTCEPSS rescore
Show 75 more
  1. 2026-08-24 14:17 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-17 13:47 UTCEPSS rescore
  9. 2026-08-16 14:56 UTCEPSS rescore
  10. 2026-08-16 02:14 UTCEPSS rescore
  11. 2026-08-15 01:30 UTCEPSS rescore
  12. 2026-08-15 01:05 UTCVendor advisory
  13. 2026-08-15 01:05 UTCGHSA enrichment
  14. 2026-08-14 21:28 UTCVendor advisory
  15. 2026-08-14 21:28 UTCGHSA enrichment
  16. 2026-08-14 16:22 UTCVendor advisory
  17. 2026-08-14 16:22 UTCGHSA enrichment
  18. 2026-08-14 12:45 UTCVendor advisory
  19. 2026-08-14 12:45 UTCGHSA enrichment
  20. 2026-08-14 09:07 UTCEG score recompute
  21. 2026-08-14 09:07 UTCVendor advisory
  22. 2026-08-14 09:07 UTCGHSA enrichment
  23. 2026-08-13 22:00 UTCEPSS rescore
  24. 2026-08-13 04:44 UTCVendor advisory
  25. 2026-08-13 04:44 UTCGHSA enrichment
  26. 2026-08-13 01:07 UTCEG score recompute
  27. 2026-08-13 01:07 UTCVendor advisory
  28. 2026-08-13 01:07 UTCGHSA enrichment
  29. 2026-08-12 13:50 UTCEPSS rescore
  30. 2026-08-12 00:54 UTCEG score recompute
  31. 2026-08-12 00:54 UTCVendor advisory
  32. 2026-08-12 00:54 UTCGHSA enrichment
  33. 2026-08-11 06:37 UTCEG score recompute
  34. 2026-08-11 06:37 UTCVendor advisory
  35. 2026-08-11 06:37 UTCGHSA enrichment
  36. 2026-08-11 00:00 UTCEPSS rescore
  37. 2026-08-10 13:18 UTCVendor advisory
  38. 2026-08-10 13:18 UTCGHSA enrichment
  39. 2026-08-10 08:54 UTCVendor advisory
  40. 2026-08-10 08:54 UTCGHSA enrichment
  41. 2026-08-10 04:47 UTCVendor advisory
  42. 2026-08-10 04:47 UTCGHSA enrichment
  43. 2026-08-10 01:00 UTCVendor advisory
  44. 2026-08-10 01:00 UTCGHSA enrichment
  45. 2026-08-09 21:23 UTCVendor advisory
  46. 2026-08-09 21:23 UTCGHSA enrichment
  47. 2026-08-09 17:46 UTCVendor advisory
  48. 2026-08-09 17:46 UTCGHSA enrichment
  49. 2026-08-09 13:51 UTCEG score recompute
  50. 2026-08-09 13:51 UTCVendor advisory
  51. 2026-08-09 13:51 UTCGHSA enrichment
  52. 2026-08-09 13:46 UTCEPSS rescore
  53. 2026-08-09 08:44 UTCVendor advisory
  54. 2026-08-09 08:44 UTCGHSA enrichment
  55. 2026-08-08 11:48 UTCVendor advisory
  56. 2026-08-08 11:48 UTCGHSA enrichment
  57. 2026-08-08 07:44 UTCVendor advisory
  58. 2026-08-08 07:44 UTCGHSA enrichment
  59. 2026-08-08 04:07 UTCVendor advisory
  60. 2026-08-08 04:07 UTCGHSA enrichment
  61. 2026-08-08 00:29 UTCVendor advisory
  62. 2026-08-08 00:29 UTCGHSA enrichment
  63. 2026-08-07 20:52 UTCEG score recompute
  64. 2026-08-07 20:52 UTCVendor advisory
  65. 2026-08-07 20:52 UTCGHSA enrichment
  66. 2026-08-06 13:46 UTCEPSS rescore
  67. 2026-08-06 06:44 UTCVendor advisory
  68. 2026-08-06 06:44 UTCGHSA enrichment
  69. 2026-08-06 03:07 UTCEG score recompute
  70. 2026-08-06 03:07 UTCVendor advisory
  71. 2026-08-06 03:07 UTCGHSA enrichment
  72. 2026-08-05 19:17 UTCEPSS rescore
  73. 2026-08-04 15:10 UTCEPSS rescore
  74. 2026-08-04 05:58 UTCEG score recompute
  75. 2026-08-04 05:58 UTCVendor advisory

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-2786?
CVE-2026-2786 is a critical vulnerability published on February 24, 2026. Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 148, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
When was CVE-2026-2786 disclosed?
CVE-2026-2786 was first published in the National Vulnerability Database on February 24, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-2786 actively exploited?
CVE-2026-2786 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 75.5% of all scored CVEs.
What is the CVSS score of CVE-2026-2786?
CVE-2026-2786 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-2786?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-2786, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-2786

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