After May 9, 2017, devices running Windows 10 version 1507 will no longer receive security updates.

US-CERT encourages users and administrators to review Microsoft’s Windows 10 version 1507 post for more information and to apply necessary updates.

via: https://www.us-cert.gov/ncas/current-activity/2017/05/04/Microsoft-Ending-Security-Updates-Windows-10-version-1507