CVE-2026-12327

HIGHPre-NVD 8.18.1—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.1 under CISA-ADP (Vulnrichment) CVSS v3.1 (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 67% of all CVEs by exploit prediction. GitHub Security Advisory enrichment pending alignment with NVD CVSS.

Triggered by: NVD CVSS baseline
Sources: cisa-adp, epss, ghsa
Trending — 4 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

A fix is available — apply it.

Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, 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, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

CVSS v3
8.1
EG Score
8.1(medium)
EG Risk
41(Track)
EG Risk 41/100SSVC: 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
Severity81% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
33.2%
KEV
Not listed

Published

June 16, 2026

Last Modified

June 17, 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

Client Challenge

https://bugzilla.mozilla.org/buglist.cgi?bug_id=2011842%2C2023902%2C2025512%2C2027312%2C2029444%2C2036571%2C2036900%2C2036936%2C2037995%2C2038551%2C2040717%2C2042724

Vendor Advisories for CVE-2026-12327(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.el9_62026-07-13redhat
redhatfirefox-0:140.12.0-1.el7_92026-07-13redhat
redhatfirefox-0:140.12.0-1.el9_42026-07-13redhat
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.el9_62026-07-09redhat
redhatfirefox-0:140.12.0-1.el8_62026-07-09redhat
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.el8_82026-07-07redhat
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 / 128× 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 152 total refreshes for this CVE.

  1. 2026-07-23 03:05 UTCEG score recompute▲ 0.80
  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. 2026-07-16 22:41 UTCVendor advisory
  9. 2026-07-16 22:41 UTCGHSA enrichment
  10. 2026-07-16 17:02 UTCEPSS rescore
  11. 2026-07-16 08:26 UTCVendor advisory
  12. 2026-07-16 08:26 UTCGHSA enrichment
  13. 2026-07-15 19:40 UTCVendor advisory
  14. 2026-07-15 19:40 UTCGHSA enrichment
  15. 2026-07-15 16:57 UTCEPSS rescore
  16. 2026-07-15 07:34 UTCVendor advisory
  17. 2026-07-15 07:34 UTCGHSA enrichment
  18. 2026-07-15 02:00 UTCEPSS rescore
  19. 2026-07-14 19:53 UTCVendor advisory
  20. 2026-07-14 19:53 UTCGHSA enrichment
  21. 2026-07-14 07:26 UTCVendor advisory
  22. 2026-07-14 07:26 UTCGHSA enrichment
  23. 2026-07-13 22:30 UTCEPSS rescore
  24. 2026-07-13 19:48 UTCVendor advisory
  25. 2026-07-13 19:48 UTCGHSA enrichment
Show 75 more
  1. 2026-07-13 07:51 UTCVendor advisory
  2. 2026-07-13 07:51 UTCGHSA enrichment
  3. 2026-07-13 06:12 UTCEPSS rescore
  4. 2026-07-12 20:13 UTCVendor advisory
  5. 2026-07-12 20:13 UTCGHSA enrichment
  6. 2026-07-12 08:35 UTCVendor advisory
  7. 2026-07-12 08:35 UTCGHSA enrichment
  8. 2026-07-12 05:46 UTCEPSS rescore
  9. 2026-07-11 20:57 UTCVendor advisory
  10. 2026-07-11 20:57 UTCGHSA enrichment
  11. 2026-07-11 09:19 UTCVendor advisory
  12. 2026-07-11 09:19 UTCGHSA enrichment
  13. 2026-07-11 08:27 UTCEPSS rescore
  14. 2026-07-10 21:41 UTCVendor advisory
  15. 2026-07-10 21:41 UTCGHSA enrichment
  16. 2026-07-10 10:04 UTCVendor advisory
  17. 2026-07-10 10:03 UTCGHSA enrichment
  18. 2026-07-09 22:01 UTCVendor advisory
  19. 2026-07-09 22:01 UTCGHSA enrichment
  20. 2026-07-09 19:10 UTCEPSS rescore
  21. 2026-07-09 10:20 UTCVendor advisory
  22. 2026-07-09 10:20 UTCGHSA enrichment
  23. 2026-07-08 22:41 UTCVendor advisory
  24. 2026-07-08 22:41 UTCGHSA enrichment
  25. 2026-07-08 15:15 UTCEPSS rescore
  26. 2026-07-08 15:15 UTCEPSS rescore
  27. 2026-07-08 11:04 UTCVendor advisory
  28. 2026-07-08 11:03 UTCGHSA enrichment
  29. 2026-07-07 23:26 UTCVendor advisory
  30. 2026-07-07 23:26 UTCGHSA enrichment
  31. 2026-07-07 13:46 UTCEPSS rescore
  32. 2026-07-07 11:47 UTCVendor advisory
  33. 2026-07-07 11:47 UTCGHSA enrichment
  34. 2026-07-06 23:16 UTCVendor advisory
  35. 2026-07-06 23:16 UTCGHSA enrichment
  36. 2026-07-06 16:27 UTCEPSS rescore
  37. 2026-07-06 02:23 UTCEPSS rescore
  38. 2026-07-06 00:10 UTCVendor advisory
  39. 2026-07-06 00:10 UTCGHSA enrichment
  40. 2026-07-05 12:31 UTCVendor advisory
  41. 2026-07-05 12:31 UTCGHSA enrichment
  42. 2026-07-05 02:30 UTCEPSS rescore
  43. 2026-07-05 02:30 UTCEPSS rescore
  44. 2026-07-05 00:44 UTCVendor advisory
  45. 2026-07-05 00:44 UTCGHSA enrichment
  46. 2026-07-04 13:05 UTCVendor advisory
  47. 2026-07-04 13:05 UTCGHSA enrichment
  48. 2026-07-04 06:31 UTCEPSS rescore
  49. 2026-07-04 01:28 UTCVendor advisory
  50. 2026-07-04 01:28 UTCGHSA enrichment
  51. 2026-07-03 13:49 UTCVendor advisory
  52. 2026-07-03 13:49 UTCGHSA enrichment
  53. 2026-07-02 22:53 UTCVendor advisory
  54. 2026-07-02 22:53 UTCGHSA enrichment
  55. 2026-07-02 11:15 UTCVendor advisory
  56. 2026-07-02 11:15 UTCGHSA enrichment
  57. 2026-07-01 23:12 UTCVendor advisory
  58. 2026-07-01 23:12 UTCGHSA enrichment
  59. 2026-07-01 15:06 UTCEPSS rescore
  60. 2026-07-01 15:06 UTCEPSS rescore
  61. 2026-07-01 11:33 UTCVendor advisory
  62. 2026-07-01 11:33 UTCGHSA enrichment
  63. 2026-06-30 23:54 UTCVendor advisory
  64. 2026-06-30 23:54 UTCGHSA enrichment
  65. 2026-06-30 23:22 UTCEPSS rescore
  66. 2026-06-30 12:10 UTCVendor advisory
  67. 2026-06-30 12:10 UTCGHSA enrichment
  68. 2026-06-30 00:24 UTCVendor advisory
  69. 2026-06-30 00:24 UTCGHSA enrichment
  70. 2026-06-29 14:06 UTCEPSS rescore
  71. 2026-06-29 12:46 UTCVendor advisory
  72. 2026-06-29 12:46 UTCGHSA enrichment
  73. 2026-06-29 01:08 UTCVendor advisory
  74. 2026-06-29 01:08 UTCGHSA enrichment
  75. 2026-06-28 14:07 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-12327?
CVE-2026-12327 is a high vulnerability published on June 16, 2026. Memory safety bugs present in Firefox ESR 140.11, Thunderbird ESR 140.11, 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…
When was CVE-2026-12327 disclosed?
CVE-2026-12327 was first published in the National Vulnerability Database on June 16, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-12327 actively exploited?
CVE-2026-12327 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 33.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-12327?
CVE-2026-12327 has a CVSS v3.1 base score of 8.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-12327?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-12327, 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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