KB4521863:Servicing stack update for Windows 10 version 1903: October 8, 2019
KB4515871:October 8, 2019-KB4524100 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 1903 and Windows Server 1903 RTM
KB4503308:Security Update for Adobe Flash Player: September 10, 2019
October 8, 2019—KB4517389 (OS Build 18362.418)
-Updates to improve security when using Internet Explorer and Microsoft Edge.
-Updates for verifying user names and passwords.
-Updates for storing and managing files.
Improvements and fixes
-Addresses an issue in security bulletin CVE-2019-1318 that may cause client or server computers that don’t support Extended Master Secret (EMS) RFC 7627 to have increased connection latency and CPU utilization. This issue occurs while performing full Transport Layer Security (TLS) handshakes from devices that don’t support EMS, especially on servers. EMS support has been available for all the supported versions of Windows since calendar year 2015 and is being incrementally enforced by the installation of the October 8, 2019 and later monthly updates.
-Security updates to Windows Shell, Internet Explorer, Microsoft Edge, Windows App Platform and Frameworks, Windows Cryptography, Windows Authentication, Windows Storage and Filesystems, Windows Kernel, Microsoft Scripting Engine, and Windows Server.