CVE-2026-40378

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-14. the CNA's CVSS baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:microsoft, epss, ghsa
Trending — 4 sources updated this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: None knownExposed: 0

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

Memory allocation with excessive size value in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.

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%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
66%
KEV
Not listed

Published

July 14, 2026

Last Modified

September 17, 2026

Advisory Details (1)

Auto-updated Jul 15, 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-2026-40378

Vendor Advisories for CVE-2026-40378(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 23× in last 7d / 115× 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 314 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-40378?
CVE-2026-40378 is a high vulnerability published on July 14, 2026. Memory allocation with excessive size value in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.
When was CVE-2026-40378 disclosed?
CVE-2026-40378 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-40378 actively exploited?
CVE-2026-40378 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 33.9% of all scored CVEs.
What is the CVSS score of CVE-2026-40378?
CVE-2026-40378 has a CVSS v4.0 base score of 7.5 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-40378?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-40378, 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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