CVE-2026-12307

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory published 2026-06-16. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this week
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

A fix is available — apply it.

Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
17.7%
KEV
Not listed

Published

June 16, 2026

Last Modified

June 18, 2026

Advisory Details (5)

Auto-updated Jun 16, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 140.12 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-61/
generic

Security Vulnerabilities fixed in Thunderbird 152 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-60/
generic

Security Vulnerabilities fixed in Firefox ESR 140.12 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-58/
generic

Security Vulnerabilities fixed in Firefox 152 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-57/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2038133

Vendor Advisories for CVE-2026-12307(20)

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

Patch Availability(21)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatthunderbird-0:140.12.0-1.el9_22026-07-15redhat
redhatthunderbird-0:140.12.0-1.el8_62026-07-14redhat
redhatthunderbird-0:140.12.0-1.el8_82026-07-14redhat
redhatthunderbird-0:140.12.0-1.el8_42026-07-14redhat
redhatfirefox-0:140.12.0-1.el9_42026-07-13redhat
redhatfirefox-0:140.12.0-1.el7_92026-07-13redhat
redhatthunderbird-0:140.12.0-1.el9_62026-07-13redhat
redhatthunderbird-0:140.12.0-1.el10_02026-07-13redhat
redhatthunderbird-0:140.12.0-1.el9_42026-07-13redhat
redhatfirefox-0:140.12.0-1.el8_62026-07-09redhat
redhatfirefox-0:140.12.0-1.el9_62026-07-09redhat
redhatfirefox-0:140.12.0-1.el8_82026-07-07redhat
redhatfirefox-0:140.12.0-1.el10_02026-07-07redhat
redhatfirefox-0:140.12.0-1.el8_42026-07-07redhat
redhatfirefox-0:140.12.0-1.el9_22026-07-07redhat
redhatthunderbird-0:140.12.0-1.el8_102026-06-30redhat
redhatthunderbird-0:140.12.0-1.el10_22026-06-29redhat
redhatthunderbird-0:140.12.0-1.el9_82026-06-25redhat
redhatfirefox-0:140.12.0-1.el10_22026-06-22redhat
redhatfirefox-0:140.12.0-1.el8_102026-06-22redhat
redhatfirefox-0:140.12.0-1.el9_82026-06-22redhat

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.

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

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 12× in last 7d / 88× 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 105 total refreshes for this CVE.

  1. 2026-07-23 03:05 UTCEG score recompute
  2. 2026-07-22 14:08 UTCEPSS rescore
  3. 2026-07-21 15:24 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 14:30 UTCEPSS rescore
  6. 2026-07-19 02:28 UTCEPSS rescore
  7. 2026-07-18 10:04 UTCEPSS rescore
  8. 2026-07-17 06:09 UTCVendor advisory
  9. 2026-07-17 06:09 UTCGHSA enrichment
  10. 2026-07-16 17:02 UTCEPSS rescore
  11. 2026-07-16 08:27 UTCVendor advisory
  12. 2026-07-16 08:27 UTCGHSA enrichment
  13. 2026-07-15 16:57 UTCEPSS rescore
  14. 2026-07-15 09:53 UTCVendor advisory
  15. 2026-07-15 09:53 UTCGHSA enrichment
  16. 2026-07-15 02:00 UTCEPSS rescore
  17. 2026-07-14 11:45 UTCVendor advisory
  18. 2026-07-14 11:45 UTCGHSA enrichment
  19. 2026-07-13 22:30 UTCEPSS rescore
  20. 2026-07-13 12:59 UTCVendor advisory
  21. 2026-07-13 12:59 UTCGHSA enrichment
  22. 2026-07-13 06:12 UTCEPSS rescore
  23. 2026-07-12 15:15 UTCVendor advisory
  24. 2026-07-12 15:15 UTCGHSA enrichment
  25. 2026-07-12 05:46 UTCEPSS rescore
Show 75 more
  1. 2026-07-11 17:27 UTCVendor advisory
  2. 2026-07-11 17:27 UTCGHSA enrichment
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-10 19:45 UTCVendor advisory
  5. 2026-07-10 19:44 UTCGHSA enrichment
  6. 2026-07-09 22:01 UTCVendor advisory
  7. 2026-07-09 22:01 UTCGHSA enrichment
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-09 00:15 UTCVendor advisory
  10. 2026-07-09 00:14 UTCGHSA enrichment
  11. 2026-07-08 15:15 UTCEPSS rescore
  12. 2026-07-08 15:15 UTCEPSS rescore
  13. 2026-07-08 02:32 UTCVendor advisory
  14. 2026-07-08 02:32 UTCGHSA enrichment
  15. 2026-07-07 13:46 UTCEPSS rescore
  16. 2026-07-07 04:47 UTCVendor advisory
  17. 2026-07-07 04:47 UTCGHSA enrichment
  18. 2026-07-06 16:27 UTCEPSS rescore
  19. 2026-07-06 06:49 UTCVendor advisory
  20. 2026-07-06 06:49 UTCGHSA enrichment
  21. 2026-07-06 02:23 UTCEPSS rescore
  22. 2026-07-05 08:45 UTCVendor advisory
  23. 2026-07-05 08:45 UTCGHSA enrichment
  24. 2026-07-05 02:30 UTCEPSS rescore
  25. 2026-07-05 02:30 UTCEPSS rescore
  26. 2026-07-04 09:22 UTCVendor advisory
  27. 2026-07-04 09:22 UTCGHSA enrichment
  28. 2026-07-04 06:31 UTCEPSS rescore
  29. 2026-07-03 06:45 UTCVendor advisory
  30. 2026-07-03 06:45 UTCGHSA enrichment
  31. 2026-07-02 07:36 UTCVendor advisory
  32. 2026-07-02 07:36 UTCGHSA enrichment
  33. 2026-07-01 15:06 UTCEPSS rescore
  34. 2026-07-01 15:06 UTCEPSS rescore
  35. 2026-07-01 09:53 UTCVendor advisory
  36. 2026-07-01 09:53 UTCGHSA enrichment
  37. 2026-06-30 23:22 UTCEPSS rescore
  38. 2026-06-30 12:10 UTCVendor advisory
  39. 2026-06-30 12:10 UTCGHSA enrichment
  40. 2026-06-29 14:06 UTCEPSS rescore
  41. 2026-06-29 13:25 UTCVendor advisory
  42. 2026-06-29 13:25 UTCGHSA enrichment
  43. 2026-06-28 15:42 UTCVendor advisory
  44. 2026-06-28 15:42 UTCGHSA enrichment
  45. 2026-06-28 14:07 UTCEPSS rescore
  46. 2026-06-28 04:56 UTCEPSS rescore
  47. 2026-06-28 04:56 UTCEPSS rescore
  48. 2026-06-27 17:57 UTCVendor advisory
  49. 2026-06-27 17:57 UTCGHSA enrichment
  50. 2026-06-27 03:08 UTCEPSS rescore
  51. 2026-06-26 20:14 UTCVendor advisory
  52. 2026-06-26 20:14 UTCGHSA enrichment
  53. 2026-06-25 22:32 UTCVendor advisory
  54. 2026-06-25 22:32 UTCGHSA enrichment
  55. 2026-06-25 13:49 UTCEPSS rescore
  56. 2026-06-25 00:49 UTCVendor advisory
  57. 2026-06-25 00:48 UTCGHSA enrichment
  58. 2026-06-24 14:05 UTCEPSS rescore
  59. 2026-06-24 03:06 UTCVendor advisory
  60. 2026-06-24 03:06 UTCGHSA enrichment
  61. 2026-06-23 21:32 UTCEPSS rescore
  62. 2026-06-23 05:18 UTCVendor advisory
  63. 2026-06-23 05:17 UTCGHSA enrichment
  64. 2026-06-22 14:25 UTCEPSS rescore
  65. 2026-06-22 14:25 UTCEPSS rescore
  66. 2026-06-22 07:30 UTCGHSA enrichment
  67. 2026-06-21 14:56 UTCEPSS rescore
  68. 2026-06-21 14:56 UTCEPSS rescore
  69. 2026-06-21 09:46 UTCGHSA enrichment
  70. 2026-06-21 01:59 UTCEPSS rescore
  71. 2026-06-21 01:59 UTCEPSS rescore
  72. 2026-06-20 12:02 UTCGHSA enrichment
  73. 2026-06-19 19:25 UTCEPSS rescore
  74. 2026-06-19 14:19 UTCEG score recompute▲ 5.30
  75. 2026-06-19 14:18 UTCGHSA enrichment

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-12307?
CVE-2026-12307 is a medium vulnerability published on June 16, 2026. Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.
When was CVE-2026-12307 disclosed?
CVE-2026-12307 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12307 actively exploited?
CVE-2026-12307 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 17.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12307?
CVE-2026-12307 has a CVSS v3.1 base score of 5.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-12307?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12307, 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-2026-12307

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