Summary

This security update resolves vulnerabilities in Microsoft Windows. The most severe of the vulnerabilities could allow remote code execution if an authenticated attacker on a guest operating system runs a specially crafted application that causes the Hyper-V host operating system to execute arbitrary code. Customers who have not enabled the Hyper-V role are not affected.To learn more about the vulnerability, see Microsoft Security Bulletin MS16-045.

More Information

Important

  • All future security and non-security updates for Windows RT 8.1, Windows 8.1, and Windows Server 2012 R2 require update 2919355 to be installed. We recommend that you install update 2919355 on your Windows RT 8.1-based, Windows 8.1-based, or Windows Server 2012 R2-based computer so that you receive future updates.

  • If you install a language pack after you install this update, you must reinstall this update. Therefore, we recommend that you install any language packs that you need before you install this update. For more information, see Add language packs to Windows.

Additional information about this security update

The following articles contain additional information about this security update as it relates to individual product versions. The articles may contain known issue information.

  • 3135456 MS16-045: Description of the security update for Windows Hyper-V: April 12, 2016

  • 3147461 Cumulative Update for Windows 10: April 12, 2016

How to obtain and install the update

Method 1: Windows Update

This update is available through Windows Update. When you turn on automatic updating, this update will be downloaded and installed automatically. For more information about how to turn on automatic updating, see Get security updates automatically.Note For Windows RT 8.1, this update is available through Windows Update only.

You can obtain the stand-alone update package through the Microsoft Download Center. Follow the installation instructions on the download page to install the update.Click the download link in Microsoft Security Bulletin MS16-045 that corresponds to the version of Windows that you are running.

Windows 8.1 (all editions)Reference TableThe following table contains the security update information for this software.

Security update file name

For all supported x64-based editions of Windows 8.1:Windows8.1-KB3135456-x64.msu

Installation switches

See Microsoft Knowledge Base Article 934307

Restart requirement

A system restart is required after you apply this security update.

Removal information

To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.

File information

See Microsoft Knowledge Base Article 3135456

Registry key verification

Note A registry key does not exist to validate the presence of this update.

Windows Server 2012 and Windows Server 2012 R2 (all editions)Reference TableThe following table contains the security update information for this software.

Security update file name

For all supported editions of Windows Server 2012:Windows8-RT-KB3135456-x64.msu

For all supported editions of Windows Server 2012 R2:Windows8.1-KB3135456-x64.msu

Installation switches

See Microsoft Knowledge Base Article 934307

Restart requirement

A system restart is required after you apply this security update.

Removal information

To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.

File information

See Microsoft Knowledge Base Article 3135456

Registry key verification

Note A registry key does not exist to validate the presence of this update.

Windows 10 (all editions)Reference TableThe following table contains the security update information for this software.

Security update file name

For all supported x64-based editions of Windows 10:Windows10.0-KB3147461-x86.msu

Installation switches

See Microsoft Knowledge Base Article 934307

Restart requirement

A system restart is required after you apply this security update.

Removal information

To uninstall an update installed by WUSA, use the /Uninstall setup switch or click Control Panel, click System and Security, click Windows Update, and then under See also, click Installed updates and select from the list of updates.

File information

See Microsoft Knowledge Base Article 3147461

Registry key verification

Note A registry key does not exist to validate the presence of this update.

Help for installing updates: Support for Microsoft UpdateSecurity solutions for IT professionals: TechNet Security Troubleshooting and SupportHelp for protecting your Windows-based computer from viruses and malware: Virus Solution and Security CenterLocal support according to your country: International Support

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