CVE-2026-8388

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2026-05-12. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

A fix is available — apply it.

Incorrect boundary conditions in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
15.5%
KEV
Not listed

Published

May 12, 2026

Last Modified

June 30, 2026

Advisory Details (5)

Auto-updated Jun 13, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 140.11 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-51/
generic

Security Vulnerabilities fixed in Firefox ESR 140.11 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-48/
generic

Security Vulnerabilities fixed in Firefox ESR 115.36 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-47/
generic

Security Vulnerabilities fixed in Firefox 150.0.3 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-45/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2036978

Vendor Advisories for CVE-2026-8388(20)

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.

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 10× in last 7d / 68× 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 108 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-8388?
CVE-2026-8388 is a medium vulnerability published on May 12, 2026. Incorrect boundary conditions in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.
When was CVE-2026-8388 disclosed?
CVE-2026-8388 was first published in the National Vulnerability Database on May 12, 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-2026-8388 actively exploited?
CVE-2026-8388 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 15.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8388?
CVE-2026-8388 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-8388?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8388, 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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