IMPORTANT This is a required security update that expands the out-of-band update dated September 23, 2019. This security update includes the Internet Explorer scripting engine security vulnerability (CVE-2019-1367) mitigation and corrects a recent printing issue some users have experienced. Customers using Windows Update or Windows Server Update Services (WSUS) will be offered this update automatically. To help secure your devices, we recommend that you install this update as soon as a possible and restart your PC to fully apply the mitigations. Like all cumulative updates, this update supersedes any preceding update.
Note This update does not replace the upcoming October 2019 monthly update, which is scheduled to release on October 8, 2019.
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.
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.
- Updates an intermittent issue with the print spooler service that may cause print jobs to fail.
Improvements and fixes
This security update includes quality improvements. Key changes include:
- Addresses an intermittent issue with the print spooler service that may cause print jobs to fail. Some apps may close or generate errors, such as the remote procedure call (RPC) error.
- Addresses an issue that may result in an error when you install Features On Demand (FOD), such as .Net 3.5. The error is, "The changes couldn’t be complete. Please reboot your computer and try again. Error code: 0x800f0950.”
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.
Known issues in this update
|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:
|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.
|This issue is resolved in KB4520008.|
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.
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.
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 10Classification: Security Updates
For a list of the files that are provided in this update, download the file information for cumulative update 4524149.