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/

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 9× in last 7d / 50× 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 315 total refreshes for this CVE.

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

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 69.1% 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

Explore →

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