CVE-2026-12305

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-06-16. 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 — 4 sources updated 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.

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
7.5
EG Score
7.5(medium)
EG Risk
38(Track)
EG Risk 38/100SSVC: 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%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
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=2037290

Vendor Advisories for CVE-2026-12305(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
redhatthunderbird-0:140.12.0-1.el9_42026-07-13redhat
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_62026-07-13redhat
redhatfirefox-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.el8_42026-07-07redhat
redhatfirefox-0:140.12.0-1.el10_02026-07-07redhat
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.el8_102026-06-22redhat
redhatfirefox-0:140.12.0-1.el10_22026-06-22redhat
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.

Affected Packages

(8 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.1.0esr-1 ... 91.9.1esr-1~deb9u1 (279 versions)140.12.0esr-1~deb11u1—
thunderbird1:102.0.1-1 ... 1:91.9.0-1~deb9u1 (330 versions)1:140.12.0esr-1~deb11u1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr102.11.0esr-1 ... 140.9.1esr-1~deb13u1 (186 versions)140.12.0esr-1~deb12u1—
thunderbird1:102.11.0-1 ... 1:140.9.1esr-1~deb13u1 (215 versions)1:140.12.0esr-1~deb12u1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (62 versions)140.12.0esr-1~deb13u1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (71 versions)1:140.12.0esr-1~deb13u1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr128.13.0esr-1 ... 140.9.1esr-1~deb13u1 (63 versions)140.12.0esr-1—
thunderbird1:128.13.0esr-1 ... 1:140.9.1esr-1~deb13u1 (72 versions)1:140.12.0esr-1—

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 7× in last 7d / 43× 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 316 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-12305?
CVE-2026-12305 is a high 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-2026-12305 disclosed?
CVE-2026-12305 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-2026-12305 actively exploited?
CVE-2026-12305 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 68.8% of all scored CVEs.
What is the CVSS score of CVE-2026-12305?
CVE-2026-12305 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-12305?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12305, 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-2026-12305

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