Description of the security update for the Remote Code Execution vulnerability in SQL Server 2016 SP2 (CU): August 21, 2018

Applies to: SQL Server 2016


A buffer overflow vulnerability exists in Microsoft SQL Server that could allow remote code execution on an affected system. An attacker who successfully exploits this vulnerability could execute code in the context of the SQL Server Database Engine service account.

To learn more about the vulnerability, see CVE-2018-8273.

This update is a replacement for the update KB4293807 that was released on August 14, 2018.  If you have previously applied the original update KB4293807, we recommend that you install the update KB4458621 as soon as possible.

You can optionally first uninstall update KB 4293807, but this is not necessary because update KB 4458621 supersedes and replaces KB 4293807.

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 Windows Update: FAQ.

Method 2: Microsoft Update Catalog

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

Method 3: Microsoft Download Center

The following file is available for download from the Microsoft Download Center:

Download the package now
Release Date: August 21, 2018

For more information about how to download Microsoft support files, click the following article number to go to the article in the Microsoft Knowledge Base:

Microsoft scanned this file for viruses by using the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

Important 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.

Deployment information

For deployment details for this security update, go to the following article in the Microsoft Knowledge Base:

More information

File hash information

File name SHA1 hash SHA256 hash
SQLServer2016-KB4458621-x64.exe B9943968AE9B91B06AE1795ADB01C891BE63B5B7 1B63456FE0742F8896F9E0202A97E412D1E54017E8BD9A086836372A9D57D097

File information

The English (United States) version of this software update installs files that have the attributes that are listed in the following tables. The dates and times for these files are listed in Coordinated Universal Time (UTC). The dates and times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and times may change when you perform certain operations on the files.

How to obtain help and support for this security update

Help for installing updates: Windows Update: FAQ

Security solutions for IT professionals: TechNet Security Support and Troubleshooting

Help for protecting your Windows-based computer from viruses and malware: Microsoft Secure

Local support according to your country: International Support