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
8.8EG
EchelonGraph verdictPlan mitigationSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.1%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is referenced (a reference tagged "Patch", often a source commit), but no release containing it is confirmed — find the release that contains it; until it is applied, mitigate (WAF / firewall / segmentation).

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

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

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
Severity88% × 45%
Exploitation1% × 40%
Automatability0% × 15%
EPSS PROB
1.1%
EPSS %ILE
63rd
KEV
Not listed

Published

May 12, 2026

Last Modified

August 10, 2026

Advisory Details (1)

Auto-updated May 12, 2026
Fix referenced — no release confirmed yet. Sources: microsoft.
microsoftMentions a patch (unverified)

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 7× in last 7d / 23× 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 282 total refreshes for this CVE.

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

Related CVEs(same CWE)

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 on May 12, 2026, with the most recent update on August 10, 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 1.1% probability of exploitation in the next 30 days (63rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40365?
CVE-2026-40365 has a CVSS base score of 8.8 (the CNA's own assessment, by microsoft; NVD's own analysis pending).
How do I remediate CVE-2026-40365?
A fix for CVE-2026-40365 is referenced (a reference tagged "Patch", often a source commit), but EchelonGraph has no release containing it on record. Check that reference and the vendor's advisory for a release that contains the fix and update to it; until then, restrict network exposure of the affected system or apply the vendor's mitigation. The vendor advisories EchelonGraph has for CVE-2026-40365 are linked in the Vendor Advisories panel on this page.

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