CVE-2026-40407

Windows Common Log File System Driver Elevation of Privilege Vulnerability

CVE-2026-40407 is fixed in 31 products on 1 platform, first by KB5087537, released May 12, 2026. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
7.8
Important
Exploitation
None reported
Exploitation Unlikely
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0030
23rd percentile

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

Where it's fixed

ProductFixed inFixReleased
Microsoft
Windows 10 Version 1607 for 32-bit Systems 14393.9140 KB5087537 May 12, 2026
Windows 10 Version 1607 for x64-based Systems 14393.9140 KB5087537 May 12, 2026
Windows 10 Version 1809 for 32-bit Systems 17763.8755 KB5087538 May 12, 2026
Windows 10 Version 1809 for x64-based Systems 17763.8755 KB5087538 May 12, 2026
Windows 10 Version 21H2 for 32-bit Systems KB5087544 May 12, 2026
Windows 10 Version 21H2 for ARM64-based Systems KB5087544 May 12, 2026
Windows 10 Version 21H2 for x64-based Systems KB5087544 May 12, 2026
Windows 10 Version 22H2 for 32-bit Systems KB5094127 Jun 9, 2026
Windows 10 Version 22H2 for ARM64-based Systems KB5094127 Jun 9, 2026
Windows 10 Version 22H2 for x64-based Systems KB5094127 Jun 9, 2026
Windows 11 Version 23H2 for ARM64-based Systems 22631.7079 KB5087420 May 12, 2026
Windows 11 Version 23H2 for x64-based Systems 22631.7219 KB5093998 Jun 9, 2026
Windows 11 Version 24H2 for ARM64-based Systems KB5089549 May 12, 2026
Windows 11 Version 24H2 for ARM64-based Systems KB5089466 May 12, 2026
Windows 11 Version 24H2 for x64-based Systems KB5089549 May 12, 2026
Windows 11 Version 24H2 for x64-based Systems KB5089466 May 12, 2026
Windows 11 Version 25H2 for ARM64-based Systems KB5089549 May 12, 2026
Windows 11 Version 25H2 for ARM64-based Systems KB5089466 May 12, 2026
Windows 11 Version 25H2 for x64-based Systems KB5089549 May 12, 2026
Windows 11 Version 25H2 for x64-based Systems KB5089466 May 12, 2026
Windows 11 Version 26H1 for ARM64-based Systems 28000.2113 KB5089548 May 12, 2026
Windows 11 version 26H1 for x64-based Systems 28000.2113 KB5089548 May 12, 2026
Windows Server 2012 KB5087470 May 12, 2026
Windows Server 2012 (Server Core installation) KB5087470 May 12, 2026
Windows Server 2012 R2 KB5087471 May 12, 2026
Windows Server 2012 R2 (Server Core installation) KB5087471 May 12, 2026
Windows Server 2016 14393.9140 KB5087537 May 12, 2026
Windows Server 2016 (Server Core installation) 14393.9140 KB5087537 May 12, 2026
Windows Server 2019 17763.8755 KB5087538 May 12, 2026
Windows Server 2019 (Server Core installation) 17763.8755 KB5087538 May 12, 2026
Windows Server 2022 20348.5074 KB5087424 May 12, 2026
Windows Server 2022 20348.5139 KB5087545 May 12, 2026
Windows Server 2022 (Server Core installation) 20348.5074 KB5087424 May 12, 2026
Windows Server 2022 (Server Core installation) 20348.5139 KB5087545 May 12, 2026
Windows Server 2022, 23H2 Edition (Server Core installation) 25398.2330 KB5087541 May 12, 2026
Windows Server 2025 26100.32860 KB5087539 May 12, 2026
Windows Server 2025 26100.32772 KB5087423 May 12, 2026
Windows Server 2025 (Server Core installation) 26100.32860 KB5087539 May 12, 2026
Windows Server 2025 (Server Core installation) 26100.32772 KB5087423 May 12, 2026

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.