MS16-114: Description of the security update for Windows SMBv1 Server: September 13, 2016

Applies to: Windows Server 2012 R2 DatacenterWindows Server 2012 R2 StandardWindows Server 2012 R2 Essentials


This security update resolves a vulnerability in Microsoft Windows. On Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2 operating systems, the vulnerability could allow remote code execution if an authenticated attacker sends specially crafted packets to an affected Microsoft Server Message Block 1.0 (SMBv1) Server. The vulnerability does not impact other SMB Server versions. Although later operating systems are affected, the potential impact is denial of service.

To learn more about the vulnerability, see Microsoft Security Bulletin MS16-114.

More Information

Nonsecurity fixes that are included in this security update

  • When you try to access a domain DFS namespace (such as \\\SYSVOL) from a computer that is configured to require mutual authentication (by using the UNC Hardened Access feature), a 0xE3 Stop error may occur on the selected domain controller if the selected domain controller is running Windows Server 2008 and has security update 3161561 installed, and the SmbServerNameHardeningLevel registry entry is configured to a nonzero value on the server.
  • You may receive a Stop 07xE error in SMB when you run many copy operations on the server-side.
  • 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.

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.

Method 2: Microsoft Update Catalog

To get the stand-alone package for this update, go to the Microsoft Update Catalog website.