CVE-2026-40365

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-05-12. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
8.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 8.8Exploit: NoneExposed: 0

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

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

CVSS v3
8.8
EG Score
8.8(medium)
EPSS
57.3%
KEV
Not listed

Published

May 12, 2026

Last Modified

June 19, 2026

Advisory Details (1)

Auto-updated May 12, 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-2026-40365

Vendor Advisories for CVE-2026-40365(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 8× in last 7d / 98× 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 171 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 02:30 UTCEPSS rescore
  6. 2026-07-04 06:31 UTCEPSS rescore
  7. 2026-07-01 15:06 UTCEPSS rescore
  8. 2026-06-30 23:22 UTCEPSS rescore
  9. 2026-06-28 14:07 UTCEPSS rescore
  10. 2026-06-28 04:56 UTCEPSS rescore
  11. 2026-06-28 01:58 UTCEG score recompute
  12. 2026-06-28 01:58 UTCVendor advisory
  13. 2026-06-28 01:58 UTCGHSA enrichment
  14. 2026-06-27 08:50 UTCEG score recompute
  15. 2026-06-27 08:50 UTCVendor advisory
  16. 2026-06-27 08:50 UTCGHSA enrichment
  17. 2026-06-27 03:08 UTCEPSS rescore
  18. 2026-06-26 20:46 UTCEG score recompute
  19. 2026-06-26 20:46 UTCVendor advisory
  20. 2026-06-26 20:46 UTCGHSA enrichment
  21. 2026-06-25 21:22 UTCEG score recompute
  22. 2026-06-25 21:22 UTCVendor advisory
  23. 2026-06-25 21:22 UTCGHSA enrichment
  24. 2026-06-25 13:49 UTCEPSS rescore
  25. 2026-06-25 13:49 UTCEPSS rescore
Show 75 more
  1. 2026-06-24 14:05 UTCEPSS rescore
  2. 2026-06-23 21:33 UTCEPSS rescore
  3. 2026-06-22 14:25 UTCEPSS rescore
  4. 2026-06-22 14:25 UTCEPSS rescore
  5. 2026-06-21 14:56 UTCEPSS rescore
  6. 2026-06-21 14:56 UTCEPSS rescore
  7. 2026-06-21 01:59 UTCEPSS rescore
  8. 2026-06-19 19:25 UTCEPSS rescore
  9. 2026-06-18 17:52 UTCEPSS rescore
  10. 2026-06-18 17:52 UTCEPSS rescore
  11. 2026-06-17 17:53 UTCEPSS rescore
  12. 2026-06-16 23:57 UTCEG score recompute
  13. 2026-06-16 23:57 UTCGHSA enrichment
  14. 2026-06-16 17:52 UTCEPSS rescore
  15. 2026-06-16 05:43 UTCEG score recompute
  16. 2026-06-16 05:43 UTCVendor advisory
  17. 2026-06-16 05:43 UTCGHSA enrichment
  18. 2026-06-15 17:49 UTCEPSS rescore
  19. 2026-06-15 01:12 UTCEG score recompute
  20. 2026-06-15 01:12 UTCVendor advisory
  21. 2026-06-15 01:12 UTCGHSA enrichment
  22. 2026-06-14 13:07 UTCEG score recompute
  23. 2026-06-14 13:07 UTCVendor advisory
  24. 2026-06-14 13:07 UTCGHSA enrichment
  25. 2026-06-14 00:45 UTCEG score recompute
  26. 2026-06-14 00:45 UTCVendor advisory
  27. 2026-06-14 00:45 UTCGHSA enrichment
  28. 2026-06-13 23:00 UTCEPSS rescore
  29. 2026-06-13 09:03 UTCEG score recompute
  30. 2026-06-13 09:03 UTCVendor advisory
  31. 2026-06-13 09:03 UTCGHSA enrichment
  32. 2026-06-12 23:12 UTCEPSS rescore
  33. 2026-06-12 23:12 UTCEPSS rescore
  34. 2026-06-12 20:57 UTCEG score recompute
  35. 2026-06-12 20:57 UTCVendor advisory
  36. 2026-06-12 20:57 UTCGHSA enrichment
  37. 2026-06-12 08:51 UTCEG score recompute
  38. 2026-06-12 08:51 UTCVendor advisory
  39. 2026-06-12 08:51 UTCGHSA enrichment
  40. 2026-06-11 20:45 UTCEG score recompute
  41. 2026-06-11 20:45 UTCGHSA enrichment
  42. 2026-06-11 14:00 UTCEPSS rescore
  43. 2026-06-11 08:41 UTCEG score recompute
  44. 2026-06-11 08:41 UTCVendor advisory
  45. 2026-06-11 08:41 UTCGHSA enrichment
  46. 2026-06-10 22:18 UTCEPSS rescore
  47. 2026-06-10 20:35 UTCEG score recompute
  48. 2026-06-10 20:35 UTCVendor advisory
  49. 2026-06-10 20:35 UTCGHSA enrichment
  50. 2026-06-10 13:22 UTCEPSS rescore
  51. 2026-06-10 13:22 UTCEPSS rescore
  52. 2026-06-10 08:31 UTCEG score recompute
  53. 2026-06-10 08:31 UTCVendor advisory
  54. 2026-06-10 08:31 UTCGHSA enrichment
  55. 2026-06-09 20:27 UTCEG score recompute
  56. 2026-06-09 20:27 UTCVendor advisory
  57. 2026-06-09 20:26 UTCGHSA enrichment
  58. 2026-06-09 08:16 UTCEG score recompute
  59. 2026-06-09 08:16 UTCVendor advisory
  60. 2026-06-09 08:16 UTCGHSA enrichment
  61. 2026-06-08 20:11 UTCEG score recompute
  62. 2026-06-08 20:11 UTCVendor advisory
  63. 2026-06-08 20:11 UTCGHSA enrichment
  64. 2026-06-08 14:17 UTCEPSS rescore
  65. 2026-06-08 14:17 UTCEPSS rescore
  66. 2026-06-08 07:28 UTCEG score recompute
  67. 2026-06-08 07:28 UTCVendor advisory
  68. 2026-06-08 07:28 UTCGHSA enrichment
  69. 2026-06-07 19:24 UTCEG score recompute
  70. 2026-06-07 19:24 UTCVendor advisory
  71. 2026-06-07 19:24 UTCGHSA enrichment
  72. 2026-06-07 15:25 UTCEPSS rescore
  73. 2026-06-07 15:25 UTCEPSS rescore
  74. 2026-06-07 07:20 UTCEG score recompute
  75. 2026-06-07 07:20 UTCVendor advisory

Frequently asked(5)

What is CVE-2026-40365?
CVE-2026-40365 is a high vulnerability published on May 12, 2026. Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
When was CVE-2026-40365 disclosed?
CVE-2026-40365 was first published in the National Vulnerability Database on May 12, 2026, with the most recent update on June 19, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40365 actively exploited?
CVE-2026-40365 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 57.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-40365?
CVE-2026-40365 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-40365?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40365, 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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