October 8, 2019—KB4520008 (OS Build 17134.1069)

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Release Date:

Oct 08, 2019

Version:

OS Build 17134.1069

The Windows 10 April 2018 Update will reach end of service on November 12, 2019 for Home and Pro editions. We will begin updating devices running the Windows 10 April 2018 Update starting July 16, 2019 to help ensure that these devices remain in a serviced and secure state. For more information, see the Windows 10, version 1903 section of the release information dashboard.

Note Follow @WindowsUpdate to find out when new content is published to the release information dashboard.

Reminder March 12 and April 9 were the last two Delta updates for Windows 10, version 1803. Security and quality updates will continue to be available via the express and full cumulative update packages. For more information on this change please visit our blog.

Starting with update KB4499183, we are introducing functionality that allows you to decide when to install a feature update. You control when you get a feature update while simultaneously keeping your devices up to date. Feature updates that are available for eligible devices will appear in a separate module on the Windows Update page (Settings > Update & Security > Windows Update). If you would like to get an available update right away, select Download and install now. To find out more about this feature, please go to this blog.

When Windows 10 devices are at, or within several months of reaching, end of service, Windows Update will begin to automatically initiate a feature update. This keeps those devices supported and receiving the monthly updates that are critical to device security and ecosystem health.

ePub support ending in Microsoft Edge

Microsoft Edge will end support for e-books that use the .epub file extension over the next several months. For more information, see Download an ePub app to keep reading e-books.

For more information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, please see the following article.

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Highlights

Updates to improve security when using Internet Explorer and Microsoft Edge.
Updates for verifying user names and passwords.
Updates for storing and managing files.

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Improvements and fixes

This security update includes quality improvements. Key changes include:

Addresses an issue in the Keyboard Lockdown Subsystem that may not filter key input correctly.
Addresses an issue with the Bluetooth hardening updates, released August 13, 2019, that may cause a "0x133 DPC_WATCHDOG_VIOLATION" error.
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.
Addresses an issue with applications and printer drivers that utilize the Windows JavaScript engine (jscript.dll) for processing print jobs.
Security updates to Windows Shell, Internet Explorer, Microsoft Edge, Windows App Platform and Frameworks, Windows Cryptography, Windows Authentication, Windows Datacenter Networking , Windows Storage and Filesystems, Windows Kernel, Microsoft Scripting Engine, and Windows Server.

If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.

For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.

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Known issues in this update

Symptom	Workaround
Certain operations, such as rename, that you perform on files or folders that are on a Cluster Shared Volume (CSV) may fail with the error, “STATUS_BAD_IMPERSONATION_LEVEL (0xC00000A5)”. This occurs when you perform the operation on a CSV owner node from a process that doesn’t have administrator privilege.	Do one of the following: Perform the operation from a process that has administrator privilege. Perform the operation from a node that doesn’t have CSV ownership. Microsoft is working on a resolution and will provide an update in an upcoming release.
We are investigating reports that a small number of devices may startup to a black screen during the first logon after installing updates.	This issue is resolved in KB4519978.
After installing this update, Windows Mixed Reality Portal users may intermittently receive a “15-5” error code. In some cases, Windows Mixed Reality Portal may report that the headset is sleeping and pressing “Wake up” may appear to produce no action.	This issue is resolved in KB4519978.
When setting up a new Windows device during the Out of Box Experience (OOBE), you might be unable to create a local user when using Input Method Editor (IME). This issue might affect you if you are using the IME for Chinese, Japanese, or Korean languages. Note This issue does not affect using a Microsoft Account during OOBE.	This issue is resolved in KB4534308.
Updates for Windows released October 8, 2019 or later provide protections, tracked by CVE-2019-1318, against an attack that could allow unauthorized access to information or data within TLS connections. This type of attack is known as a man-in-the-middle exploit. Windows might fail to connect to TLS clients and servers that do not support Extended Master Secret for resumption (RFC 7627). Lack of RFC support might cause one or more of the following errors or logged events: "The request was aborted: Could not create SSL/TLS secure Channel" SCHANNEL event 36887 is logged in the System event log with the description, "A fatal alert was received from the remote endpoint. The TLS protocol defined fatal alert code is 20."	For information, see KB4528489.

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How to get this update

Before installing this update

Microsoft strongly recommends you install the latest servicing stack update (SSU) for your operating system before installing the latest cumulative update (LCU). SSUs improve the reliability of the update process to mitigate potential issues while installing the LCU and applying Microsoft security fixes. For more information, see Servicing stack updates.

If you are using Windows Update, the latest SSU (KB4521861) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.

Install this update

Release Channel	Available	Next Step
Windows Update and Microsoft Update	Yes	None. This update will be downloaded and installed automatically from Windows Update.
Microsoft Update Catalog	Yes	To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS)	Yes	This update will automatically synchronize with WSUS if you configure Products and Classifications as follows: Product: Windows 10 Classification: Security Updates