CVE-2026-8947

HIGHPre-NVD 7.37.3—
EchelonGraph scoreMEDIUM confidence

Score 7.3 from GitHub Security Advisory (severity: HIGH) published 2026-05-19. NVD baseline CVSS 7.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.3Exploit: NoneExposed: 0

A fix is available — apply it.

Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.

CVSS v3
7.3
EG Score
7.3(medium)
EPSS
33.2%
KEV
Not listed

Published

May 19, 2026

Last Modified

June 30, 2026

Advisory Details (6)

Auto-updated Jun 11, 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 Thunderbird 151 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-50/
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 151 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-46/
generic

Access Denied

https://bugzilla.mozilla.org/show_bug.cgi?id=2038439

Vendor Advisories for CVE-2026-8947(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
redhatthunderbird-0:140.11.0-1.el10_02026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_22026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_42026-06-17redhat
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.el8_82026-06-17redhat
redhatfirefox-0:140.11.0-1.el8_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el8_42026-06-17redhat
redhatthunderbird-0:140.11.0-1.el9_62026-06-17redhat
redhatfirefox-0:140.11.0-1.el9_62026-06-17redhat
redhatthunderbird-0:140.11.0-1.el8_42026-06-16redhat
redhatthunderbird-0:140.11.0-1.el9_22026-06-16redhat
redhatthunderbird-0:140.11.0-1.el9_42026-06-16redhat
redhatthunderbird-0:140.11.0-1.el8_82026-06-16redhat
redhatthunderbird-0:140.11.0-1.el8_102026-06-03redhat
redhatthunderbird-0:140.11.0-1.el10_22026-06-01redhat
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
redhatthunderbird-0:140.11.0-1.el9_82026-05-27redhat

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 9× in last 7d / 108× 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 161 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-8947?
CVE-2026-8947 is a high vulnerability published on May 19, 2026. Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
When was CVE-2026-8947 disclosed?
CVE-2026-8947 was first published in the National Vulnerability Database on May 19, 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-2026-8947 actively exploited?
CVE-2026-8947 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-2026-8947?
CVE-2026-8947 has a CVSS v3.1 base score of 7.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-8947?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8947, 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

Explore the affected products and dependency analysis for CVE-2026-8947

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