CVE-2026-12326

HIGHPre-NVD 8.17.3▼
EchelonGraph scoreHIGH confidence

Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-06-16. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 8.1; sources differ by 0.8.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 3 sources updated this week
8.1
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 8.1Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Memory safety bugs present in Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

CVSS v3
8.1
EG Score
7.3(high)
EPSS
16.3%
KEV
Not listed

Published

June 16, 2026

Last Modified

June 30, 2026

Advisory Details (5)

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

Security Vulnerabilities fixed in Thunderbird 152 — Mozilla

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

Security Vulnerabilities fixed in Firefox 152 — Mozilla

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

Client Challenge

https://bugzilla.mozilla.org/buglist.cgi?bug_id=2039050%2C2042718%2C2042760%2C2044831%2C2045307%2C2045398%2C2045516%2C2045572%2C2041741%2C2044433
generic

Client Challenge

https://bugzilla.mozilla.org/buglist.cgi?bug_id=2021955%2C2025960%2C2029066%2C2029403%2C2029435%2C2029803%2C2030570%2C2030573%2C2032264%2C2033234%2C2034816%2C2035907%2C2035963%2C2036895%2C2036898%2C2036907%2C2036909%2C2036928%2C2036931%2C2036932%2C2036934%2C2039238%2C2039463
generic

Client Challenge

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1767455%2C2004308%2C2024445%2C2028182%2C2029765%2C2029883%2C2030110%2C2030149%2C2030366%2C2030374%2C2030564%2C2031120%2C2033411%2C2038695%2C2042465%2C2042781%2C2042907

Vendor Advisories for CVE-2026-12326(1)

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

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 34× in last 7d / 99× 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. 2026-07-06 23:16 UTCEG score recompute
  2. 2026-07-06 23:16 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-06 01:11 UTCEG score recompute
  6. 2026-07-06 01:11 UTCGHSA enrichment
  7. 2026-07-05 13:27 UTCEG score recompute
  8. 2026-07-05 13:27 UTCGHSA enrichment
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-05 01:44 UTCEG score recompute
  12. 2026-07-05 01:44 UTCGHSA enrichment
  13. 2026-07-04 13:42 UTCEG score recompute
  14. 2026-07-04 13:41 UTCGHSA enrichment
  15. 2026-07-04 06:31 UTCEPSS rescore
  16. 2026-07-04 01:57 UTCEG score recompute
  17. 2026-07-04 01:57 UTCGHSA enrichment
  18. 2026-07-03 13:49 UTCEG score recompute
  19. 2026-07-03 13:49 UTCGHSA enrichment
  20. 2026-07-02 22:58 UTCEG score recompute
  21. 2026-07-02 22:58 UTCGHSA enrichment
  22. 2026-07-02 11:15 UTCEG score recompute
  23. 2026-07-02 11:15 UTCGHSA enrichment
  24. 2026-07-01 23:21 UTCEG score recompute
  25. 2026-07-01 23:21 UTCGHSA enrichment
Show 74 more
  1. 2026-07-01 15:06 UTCEPSS rescore
  2. 2026-07-01 15:06 UTCEPSS rescore
  3. 2026-07-01 11:37 UTCEG score recompute
  4. 2026-07-01 11:37 UTCGHSA enrichment
  5. 2026-06-30 23:54 UTCEG score recompute
  6. 2026-06-30 23:54 UTCGHSA enrichment
  7. 2026-06-30 23:22 UTCEPSS rescore
  8. 2026-06-30 12:10 UTCEG score recompute
  9. 2026-06-30 12:10 UTCGHSA enrichment
  10. 2026-06-29 23:53 UTCEG score recompute
  11. 2026-06-29 23:53 UTCGHSA enrichment
  12. 2026-06-29 14:06 UTCEPSS rescore
  13. 2026-06-29 12:05 UTCEG score recompute
  14. 2026-06-29 12:05 UTCGHSA enrichment
  15. 2026-06-29 00:22 UTCEG score recompute
  16. 2026-06-29 00:22 UTCGHSA enrichment
  17. 2026-06-28 14:07 UTCEPSS rescore
  18. 2026-06-28 12:38 UTCEG score recompute
  19. 2026-06-28 12:38 UTCGHSA enrichment
  20. 2026-06-28 04:56 UTCEPSS rescore
  21. 2026-06-28 04:56 UTCEPSS rescore
  22. 2026-06-28 00:55 UTCEG score recompute
  23. 2026-06-28 00:55 UTCGHSA enrichment
  24. 2026-06-27 13:12 UTCEG score recompute
  25. 2026-06-27 13:12 UTCGHSA enrichment
  26. 2026-06-27 03:08 UTCEPSS rescore
  27. 2026-06-27 01:29 UTCEG score recompute
  28. 2026-06-27 01:29 UTCGHSA enrichment
  29. 2026-06-26 13:46 UTCEG score recompute
  30. 2026-06-26 13:46 UTCGHSA enrichment
  31. 2026-06-26 02:03 UTCEG score recompute
  32. 2026-06-26 02:03 UTCGHSA enrichment
  33. 2026-06-25 14:16 UTCEG score recompute
  34. 2026-06-25 14:16 UTCGHSA enrichment
  35. 2026-06-25 13:49 UTCEPSS rescore
  36. 2026-06-25 02:32 UTCEG score recompute
  37. 2026-06-25 02:32 UTCGHSA enrichment
  38. 2026-06-24 14:49 UTCEG score recompute
  39. 2026-06-24 14:49 UTCGHSA enrichment
  40. 2026-06-24 14:05 UTCEPSS rescore
  41. 2026-06-24 03:06 UTCEG score recompute
  42. 2026-06-24 03:06 UTCGHSA enrichment
  43. 2026-06-23 21:32 UTCEPSS rescore
  44. 2026-06-23 15:22 UTCEG score recompute
  45. 2026-06-23 15:22 UTCGHSA enrichment
  46. 2026-06-23 03:39 UTCEG score recompute
  47. 2026-06-23 03:39 UTCGHSA enrichment
  48. 2026-06-22 15:48 UTCEG score recompute
  49. 2026-06-22 15:48 UTCGHSA enrichment
  50. 2026-06-22 14:25 UTCEPSS rescore
  51. 2026-06-22 14:25 UTCEPSS rescore
  52. 2026-06-22 04:03 UTCEG score recompute
  53. 2026-06-22 04:03 UTCGHSA enrichment
  54. 2026-06-21 16:19 UTCEG score recompute
  55. 2026-06-21 16:18 UTCGHSA enrichment
  56. 2026-06-21 14:56 UTCEPSS rescore
  57. 2026-06-21 14:56 UTCEPSS rescore
  58. 2026-06-21 04:11 UTCEG score recompute
  59. 2026-06-21 04:11 UTCGHSA enrichment
  60. 2026-06-21 01:59 UTCEPSS rescore
  61. 2026-06-21 01:59 UTCEPSS rescore
  62. 2026-06-20 16:17 UTCEG score recompute
  63. 2026-06-20 16:17 UTCGHSA enrichment
  64. 2026-06-20 04:32 UTCEG score recompute
  65. 2026-06-20 04:31 UTCGHSA enrichment
  66. 2026-06-19 19:25 UTCEPSS rescore
  67. 2026-06-19 16:46 UTCEG score recompute▲ 7.30
  68. 2026-06-19 16:46 UTCGHSA enrichment
  69. 2026-06-18 17:52 UTCEPSS rescore
  70. 2026-06-17 17:53 UTCEPSS rescore
  71. 2026-06-17 17:14 UTCNVD updateCVSS v3 → 8.1
  72. 2026-06-16 17:47 UTCNVD updateCVSS v3 → 7.3 · severity → HIGH
  73. 2026-06-16 13:47 UTCEG score recompute
  74. 2026-06-16 13:46 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-12326?
CVE-2026-12326 is a high vulnerability published on June 16, 2026. Memory safety bugs present in Firefox 151 and Thunderbird 151. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox 152 and Thunderbird 152.
When was CVE-2026-12326 disclosed?
CVE-2026-12326 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12326 actively exploited?
CVE-2026-12326 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 16.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12326?
CVE-2026-12326 has a CVSS v3.1 base score of 8.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 7.3.
How do I remediate CVE-2026-12326?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12326, 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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