CVE-2026-40409

HIGHPre-NVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

Score 7.8 from GitHub Security Advisory (severity: HIGH) published 2026-06-09. the CNA's CVSS baseline 7.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 3 sources updated this week
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.8Exploit: NoneExposed: 0

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

Windows Universal Disk Format File System Driver (UDFS) Elevation of Privilege Vulnerability

CVSS v3
7.8
EG Score
7.8(medium)
EPSS
22.0%
KEV
Not listed

Published

June 9, 2026

Last Modified

July 15, 2026

Advisory Details (1)

Auto-updated Jun 9, 2026
Patch available. Sources: microsoft.
microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40409

Vendor Advisories for CVE-2026-40409(2)

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 10× in last 7d / 120× 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 187 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-40409?
CVE-2026-40409 is a high vulnerability published on June 9, 2026. Windows Universal Disk Format File System Driver (UDFS) Elevation of Privilege Vulnerability
When was CVE-2026-40409 disclosed?
CVE-2026-40409 was first published in the National Vulnerability Database on June 9, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40409 actively exploited?
CVE-2026-40409 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 22.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-40409?
CVE-2026-40409 has a CVSS v4.0 base score of 7.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-40409?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40409, 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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