CVE-2026-40407HighMicrosoft CVSS 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Microsoft security update for CVE-2026-40407 — Windows

Published
May 22, 2026
Last Modified
—

🔗 CVE IDs covered (1)

CVE-2026-40407 →

📋 Microsoft's advisory

EchelonGraph does not copy Microsoft's advisory page: its FAQ and remediation text are not shown here. Read the advisory on https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40407. This page also shows what EchelonGraph holds for CVE-2026-40407, with the description from its CVE record, which the CVE Numbering Authority that assigned the CVE wrote: for a CVE Microsoft assigned, often in the words of Microsoft's own advisory.

🎯 Affected products31

  • Windows 10 Version 1607 for 32-bit Systems
  • Windows 10 Version 1607 for x64-based Systems
  • Windows 10 Version 1809 for 32-bit Systems
  • Windows 10 Version 1809 for x64-based Systems
  • Windows 10 Version 21H2 for 32-bit Systems
  • Windows 10 Version 21H2 for ARM64-based Systems
  • Windows 10 Version 21H2 for x64-based Systems
  • Windows 10 Version 22H2 for 32-bit Systems
  • Windows 10 Version 22H2 for ARM64-based Systems
  • Windows 10 Version 22H2 for x64-based Systems
  • Windows 11 Version 23H2 for ARM64-based Systems
  • Windows 11 Version 23H2 for x64-based Systems
  • Windows 11 Version 24H2 for ARM64-based Systems
  • Windows 11 Version 24H2 for x64-based Systems
  • Windows 11 Version 25H2 for ARM64-based Systems
  • Windows 11 Version 25H2 for x64-based Systems
  • Windows 11 Version 26H1 for ARM64-based Systems
  • Windows 11 version 26H1 for x64-based Systems
  • Windows Server 2012
  • Windows Server 2012 (Server Core installation)
  • Windows Server 2012 R2
  • Windows Server 2012 R2 (Server Core installation)
  • Windows Server 2016
  • Windows Server 2016 (Server Core installation)
  • Windows Server 2019
  • Windows Server 2019 (Server Core installation)
  • Windows Server 2022
  • Windows Server 2022 (Server Core installation)
  • Windows Server 2022, 23H2 Edition (Server Core installation)
  • Windows Server 2025
  • +1 more not shown

✅ Updates Microsoft lists: 16 KB articles

18 rows: one per KB article or update, update type and fixed build. Their details are on Microsoft's advisory.

KB articleUpdateFixed build
KB5087545Security Update10.0.20348.5139
KB5087424Security Hotpatch Update10.0.20348.5074
KB5087538Security Update10.0.17763.8755
KB5087544Security Update10.0.19044.7291
KB5094127Security Update10.0.19045.7417
KB5087539Security Update10.0.26100.32860
KB5087423Security Hotpatch Update10.0.26100.32772
KB5089549Security Update10.0.26200.8457
KB5089466Security Hotpatch Update10.0.26200.8390
KB5093998Security Update10.0.22631.7219
KB5087420Security Update10.0.22631.7079
KB5087541Security Update10.0.25398.2330
KB5089549Security Update10.0.26100.8457
KB5089466Security Hotpatch Update10.0.26100.8390
KB5089548Security Update10.0.28000.2113
KB5087537Security Update10.0.14393.9140
KB5087470Monthly Rollup6.2.9200.26079
KB5087471Monthly Rollup6.3.9600.23181

🧭 EchelonGraph on CVE-2026-40407

EchelonGraph score
7.8 HIGH
CISA KEV
Not listed
Fix status
A fix is available — apply it.

Description from the CVE record (CVE.org), as published by its numbering authority

Heap-based buffer overflow in Windows Common Log File System Driver allows an authorized attacker to elevate privileges locally.

Published by Microsoft Corporation, the CVE Numbering Authority that assigned CVE-2026-40407, in its CVE record at CVE.org; reused under the CVE Program's Terms of Use (its licence and MITRE's copyright notice are in our Terms of Service).

🔗 References (33)