CVE-2026-12308

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 — 3 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
—
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=2038302

Vendor Advisories for CVE-2026-12308(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_42026-07-14redhat
redhatthunderbird-0:140.12.0-1.el8_82026-07-14redhat
redhatthunderbird-0:140.12.0-1.el8_62026-07-14redhat
redhatthunderbird-0:140.12.0-1.el10_02026-07-13redhat
redhatfirefox-0:140.12.0-1.el7_92026-07-13redhat
redhatthunderbird-0:140.12.0-1.el9_42026-07-13redhat
redhatthunderbird-0:140.12.0-1.el9_62026-07-13redhat
redhatfirefox-0:140.12.0-1.el9_42026-07-13redhat
redhatfirefox-0:140.12.0-1.el9_62026-07-09redhat
redhatfirefox-0:140.12.0-1.el8_62026-07-09redhat
redhatfirefox-0:140.12.0-1.el8_82026-07-07redhat
redhatfirefox-0:140.12.0-1.el9_22026-07-07redhat
redhatfirefox-0:140.12.0-1.el10_02026-07-07redhat
redhatfirefox-0:140.12.0-1.el8_42026-07-07redhat
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 9× in last 7d / 77× 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. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:24 UTCEPSS rescore
  3. 2026-07-20 17:08 UTCEPSS rescore
  4. 2026-07-19 14:30 UTCEPSS rescore
  5. 2026-07-19 02:28 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-16 22:42 UTCVendor advisory
  8. 2026-07-16 22:42 UTCGHSA enrichment
  9. 2026-07-16 17:02 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 16:27 UTCVendor advisory
  12. 2026-07-15 16:27 UTCGHSA enrichment
  13. 2026-07-15 02:00 UTCEPSS rescore
  14. 2026-07-14 14:24 UTCVendor advisory
  15. 2026-07-14 14:24 UTCGHSA enrichment
  16. 2026-07-13 22:30 UTCEPSS rescore
  17. 2026-07-13 12:22 UTCVendor advisory
  18. 2026-07-13 12:22 UTCGHSA enrichment
  19. 2026-07-13 06:12 UTCEPSS rescore
  20. 2026-07-12 10:11 UTCVendor advisory
  21. 2026-07-12 10:11 UTCGHSA enrichment
  22. 2026-07-12 05:46 UTCEPSS rescore
  23. 2026-07-11 08:27 UTCEPSS rescore
  24. 2026-07-11 08:08 UTCVendor advisory
  25. 2026-07-11 08:08 UTCGHSA enrichment
Show 70 more
  1. 2026-07-10 06:02 UTCVendor advisory
  2. 2026-07-10 06:01 UTCGHSA enrichment
  3. 2026-07-09 19:10 UTCEPSS rescore
  4. 2026-07-09 03:27 UTCVendor advisory
  5. 2026-07-09 03:27 UTCGHSA enrichment
  6. 2026-07-08 15:15 UTCEPSS rescore
  7. 2026-07-08 15:15 UTCEPSS rescore
  8. 2026-07-08 01:21 UTCVendor advisory
  9. 2026-07-08 01:21 UTCGHSA enrichment
  10. 2026-07-07 13:46 UTCEPSS rescore
  11. 2026-07-06 23:18 UTCVendor advisory
  12. 2026-07-06 23:18 UTCGHSA enrichment
  13. 2026-07-06 16:27 UTCEPSS rescore
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-05 20:40 UTCVendor advisory
  16. 2026-07-05 20:40 UTCGHSA enrichment
  17. 2026-07-05 02:30 UTCEPSS rescore
  18. 2026-07-05 02:30 UTCEPSS rescore
  19. 2026-07-04 18:38 UTCVendor advisory
  20. 2026-07-04 18:38 UTCGHSA enrichment
  21. 2026-07-04 06:31 UTCEPSS rescore
  22. 2026-07-03 14:01 UTCVendor advisory
  23. 2026-07-03 14:01 UTCGHSA enrichment
  24. 2026-07-02 11:55 UTCVendor advisory
  25. 2026-07-02 11:55 UTCGHSA enrichment
  26. 2026-07-01 15:06 UTCEPSS rescore
  27. 2026-07-01 15:06 UTCEPSS rescore
  28. 2026-07-01 09:52 UTCVendor advisory
  29. 2026-07-01 09:52 UTCGHSA enrichment
  30. 2026-06-30 23:22 UTCEPSS rescore
  31. 2026-06-30 07:46 UTCVendor advisory
  32. 2026-06-30 07:46 UTCGHSA enrichment
  33. 2026-06-29 14:06 UTCEPSS rescore
  34. 2026-06-29 05:44 UTCVendor advisory
  35. 2026-06-29 05:44 UTCGHSA enrichment
  36. 2026-06-28 14:07 UTCEPSS rescore
  37. 2026-06-28 04:56 UTCEPSS rescore
  38. 2026-06-28 04:56 UTCEPSS rescore
  39. 2026-06-28 03:17 UTCVendor advisory
  40. 2026-06-28 03:17 UTCGHSA enrichment
  41. 2026-06-27 03:08 UTCEPSS rescore
  42. 2026-06-27 01:14 UTCVendor advisory
  43. 2026-06-27 01:14 UTCGHSA enrichment
  44. 2026-06-25 23:12 UTCVendor advisory
  45. 2026-06-25 23:12 UTCGHSA enrichment
  46. 2026-06-25 13:49 UTCEPSS rescore
  47. 2026-06-24 21:09 UTCVendor advisory
  48. 2026-06-24 21:09 UTCGHSA enrichment
  49. 2026-06-24 14:05 UTCEPSS rescore
  50. 2026-06-23 21:32 UTCEPSS rescore
  51. 2026-06-23 19:07 UTCVendor advisory
  52. 2026-06-23 19:07 UTCGHSA enrichment
  53. 2026-06-22 17:04 UTCVendor advisory
  54. 2026-06-22 17:04 UTCGHSA enrichment
  55. 2026-06-22 14:25 UTCEPSS rescore
  56. 2026-06-22 14:25 UTCEPSS rescore
  57. 2026-06-21 14:56 UTCEPSS rescore
  58. 2026-06-21 14:56 UTCEPSS rescore
  59. 2026-06-21 14:25 UTCGHSA enrichment
  60. 2026-06-21 01:59 UTCEPSS rescore
  61. 2026-06-21 01:59 UTCEPSS rescore
  62. 2026-06-20 12:23 UTCGHSA enrichment
  63. 2026-06-19 19:25 UTCEPSS rescore
  64. 2026-06-19 10:18 UTCEG score recompute▲ 5.30
  65. 2026-06-19 10:17 UTCGHSA enrichment
  66. 2026-06-18 17:52 UTCEPSS rescore
  67. 2026-06-17 17:53 UTCEPSS rescore
  68. 2026-06-16 19:48 UTCNVD updateCVSS v3 → 5.3 · severity → MEDIUM
  69. 2026-06-16 13:48 UTCEG score recompute
  70. 2026-06-16 13:46 UTCNVD updatefirst tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-12308?
CVE-2026-12308 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-2026-12308 disclosed?
CVE-2026-12308 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-2026-12308 actively exploited?
CVE-2026-12308 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-2026-12308?
CVE-2026-12308 has a CVSS v3.1 base score of 5.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-12308?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12308, 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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