CVE-2026-8401

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-05-12. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3, Firefox ESR 115.36, Firefox ESR 140.11, and Thunderbird 140.11.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
23.2%
KEV
Not listed

Published

May 12, 2026

Last Modified

June 30, 2026

Advisory Details (10)

Auto-updated Jun 30, 2026
Patch available. Sources: redhat.
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:22325
redhat Patch Available

Affected: Red Hat Enterprise Linux 8.

https://access.redhat.com/errata/RHSA-2026:21382
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:21381
redhat Patch Available

Affected: Red Hat Enterprise Linux 10.

https://access.redhat.com/errata/RHSA-2026:21380
redhat Patch Available

Affected: Red Hat Enterprise Linux 9.

https://access.redhat.com/errata/RHSA-2026:21378
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=2038679

Vendor Advisories for CVE-2026-8401(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
redhatfirefox-0:140.11.0-1.el10_02026-06-22redhat
redhatfirefox-0:140.11.0-1.el8_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el8_82026-06-17redhat
redhatthunderbird-0:140.11.0-1.el10_02026-06-17redhat
redhatfirefox-0:140.11.0-1.el7_92026-06-17redhat
redhatthunderbird-0:140.11.0-1.el8_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_42026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_22026-06-17redhat
redhatthunderbird-0:140.11.0-1.el9_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el8_42026-06-17redhat
redhatthunderbird-0:140.11.0-1.el8_82026-06-16redhat
redhatthunderbird-0:140.11.0-1.el8_42026-06-16redhat
redhatthunderbird-0:140.11.0-1.el9_42026-06-16redhat
redhatthunderbird-0:140.11.0-1.el9_22026-06-16redhat
redhatthunderbird-0:140.11.0-1.el8_102026-06-03redhat
redhatthunderbird-0:140.11.0-1.el10_22026-06-01redhat
redhatthunderbird-0:140.11.0-1.el9_82026-05-27redhat
redhatfirefox-0:140.11.0-1.el9_82026-05-27redhat
redhatfirefox-0:140.11.0-1.el8_102026-05-27redhat
redhatfirefox-0:140.11.0-1.el10_22026-05-27redhat

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(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 / 209× 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 364 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 13:29 UTCEG score recompute
  14. 2026-06-28 13:29 UTCVendor advisory
  15. 2026-06-28 13:29 UTCGHSA enrichment
  16. 2026-06-28 08:24 UTCEG score recompute
  17. 2026-06-28 08:24 UTCVendor advisory
  18. 2026-06-28 08:24 UTCGHSA enrichment
  19. 2026-06-28 04:56 UTCEPSS rescore
  20. 2026-06-28 02:21 UTCEG score recompute
  21. 2026-06-28 02:21 UTCVendor advisory
  22. 2026-06-28 02:21 UTCGHSA enrichment
  23. 2026-06-27 13:18 UTCEG score recompute
  24. 2026-06-27 13:18 UTCVendor advisory
  25. 2026-06-27 13:18 UTCGHSA enrichment
Show 75 more
  1. 2026-06-27 08:28 UTCEG score recompute
  2. 2026-06-27 08:28 UTCVendor advisory
  3. 2026-06-27 08:28 UTCGHSA enrichment
  4. 2026-06-27 03:08 UTCEPSS rescore
  5. 2026-06-26 20:55 UTCEG score recompute
  6. 2026-06-26 20:55 UTCVendor advisory
  7. 2026-06-26 20:55 UTCGHSA enrichment
  8. 2026-06-26 04:04 UTCEG score recompute
  9. 2026-06-26 04:04 UTCVendor advisory
  10. 2026-06-26 04:04 UTCGHSA enrichment
  11. 2026-06-25 23:26 UTCEG score recompute
  12. 2026-06-25 23:26 UTCVendor advisory
  13. 2026-06-25 23:26 UTCGHSA enrichment
  14. 2026-06-25 13:50 UTCEPSS rescore
  15. 2026-06-24 14:05 UTCEPSS rescore
  16. 2026-06-23 21:33 UTCEPSS rescore
  17. 2026-06-22 14:25 UTCEPSS rescore
  18. 2026-06-21 14:56 UTCEPSS rescore
  19. 2026-06-21 01:59 UTCEPSS rescore
  20. 2026-06-19 19:26 UTCEPSS rescore
  21. 2026-06-18 17:52 UTCEPSS rescore
  22. 2026-06-17 17:53 UTCEPSS rescore
  23. 2026-06-17 05:16 UTCEG score recompute
  24. 2026-06-17 05:16 UTCVendor advisory
  25. 2026-06-17 05:16 UTCGHSA enrichment
  26. 2026-06-17 00:24 UTCEG score recompute
  27. 2026-06-17 00:24 UTCVendor advisory
  28. 2026-06-17 00:24 UTCGHSA enrichment
  29. 2026-06-16 17:53 UTCEPSS rescore
  30. 2026-06-16 11:45 UTCEG score recompute
  31. 2026-06-16 11:45 UTCVendor advisory
  32. 2026-06-16 11:45 UTCGHSA enrichment
  33. 2026-06-16 06:44 UTCEG score recompute
  34. 2026-06-16 06:44 UTCVendor advisory
  35. 2026-06-16 06:44 UTCGHSA enrichment
  36. 2026-06-15 17:49 UTCEPSS rescore
  37. 2026-06-15 17:49 UTCEPSS rescore
  38. 2026-06-15 05:48 UTCEG score recompute
  39. 2026-06-15 05:48 UTCVendor advisory
  40. 2026-06-15 05:48 UTCGHSA enrichment
  41. 2026-06-15 02:05 UTCEG score recompute
  42. 2026-06-15 02:05 UTCVendor advisory
  43. 2026-06-15 02:05 UTCGHSA enrichment
  44. 2026-06-14 23:18 UTCEPSS rescore
  45. 2026-06-14 22:21 UTCEG score recompute
  46. 2026-06-14 22:21 UTCVendor advisory
  47. 2026-06-14 22:21 UTCGHSA enrichment
  48. 2026-06-14 18:29 UTCEG score recompute
  49. 2026-06-14 18:29 UTCVendor advisory
  50. 2026-06-14 18:29 UTCGHSA enrichment
  51. 2026-06-14 14:26 UTCEG score recompute
  52. 2026-06-14 14:26 UTCVendor advisory
  53. 2026-06-14 14:26 UTCGHSA enrichment
  54. 2026-06-14 10:29 UTCEG score recompute
  55. 2026-06-14 10:29 UTCVendor advisory
  56. 2026-06-14 10:28 UTCGHSA enrichment
  57. 2026-06-14 06:35 UTCEG score recompute
  58. 2026-06-14 06:35 UTCVendor advisory
  59. 2026-06-14 06:35 UTCGHSA enrichment
  60. 2026-06-14 00:59 UTCEG score recompute
  61. 2026-06-14 00:59 UTCVendor advisory
  62. 2026-06-14 00:59 UTCGHSA enrichment
  63. 2026-06-13 23:00 UTCEPSS rescore
  64. 2026-06-13 09:26 UTCEG score recompute
  65. 2026-06-13 09:26 UTCVendor advisory
  66. 2026-06-13 09:26 UTCGHSA enrichment
  67. 2026-06-13 05:42 UTCEG score recompute
  68. 2026-06-13 05:42 UTCVendor advisory
  69. 2026-06-13 05:42 UTCGHSA enrichment
  70. 2026-06-13 00:32 UTCEG score recompute
  71. 2026-06-13 00:32 UTCVendor advisory
  72. 2026-06-13 00:32 UTCGHSA enrichment
  73. 2026-06-12 23:12 UTCEPSS rescore
  74. 2026-06-12 23:12 UTCEPSS rescore
  75. 2026-06-12 20:47 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-8401?
CVE-2026-8401 is a critical vulnerability published on May 12, 2026. Sandbox escape in the Profile Backup 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-2026-8401 disclosed?
CVE-2026-8401 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-2026-8401 actively exploited?
CVE-2026-8401 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 23.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-8401?
CVE-2026-8401 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-8401?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8401, 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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