CVE-2026-8966

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-05-19. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

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

Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
26%
KEV
Not listed

Published

May 19, 2026

Last Modified

July 23, 2026

Advisory Details (3)

Auto-updated Jun 4, 2026
No patch confirmed yet.
generic

Security Vulnerabilities fixed in Thunderbird 151 — Mozilla

https://www.mozilla.org/security/advisories/mfsa2026-50/
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=2025849

Vendor Advisories for CVE-2026-8966(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 66× 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 205 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-8966?
CVE-2026-8966 is a high vulnerability published on May 19, 2026. Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.
When was CVE-2026-8966 disclosed?
CVE-2026-8966 was first published in the National Vulnerability Database on May 19, 2026, with the most recent update on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-8966 actively exploited?
CVE-2026-8966 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 74.1% of all scored CVEs.
What is the CVSS score of CVE-2026-8966?
CVE-2026-8966 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-8966?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-8966, 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.

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