KB5122774 - Description of the security update for SQL Server 2017 CU31: September 8, 2026

Applies To
SQL Server 2017 on Linux SQL Server 2017 on Windows

Release date: September 8, 2026

Version: 14.0.3550.4

Summary

This security update contains fixes and resolves vulnerabilities. To learn more about the vulnerabilities, see the following security advisories:

The Microsoft SQL Server components are updated to the following builds in this security update:

  • SQL Server - product version: 14.0.3550.4, file version: 2017.140.3550.4

Important

To help secure SQL Server on Windows, enable encryption with Extended Protection.

Known issues in this update

Linked server queries that use MSDASQL fail with error 7416

Linked server queries that use the MSDASQL (OLE DB Provider for ODBC Drivers) provider and specify a provider string (@provstr) fail and return the following error message:

Msg 7416, Level 16
Access to the remote server is denied because no login-mapping exists.

A stricter connection validation check in the Database Engine can reject connections for certain linked server configurations that use the MSDASQL provider, even if earlier builds allowed those connections.

For more information and workarounds, see Linked server queries that use MSDASQL fail with error 7416.

Improvements and fixes included in this update

A downloadable Microsoft Excel workbook that contains a summary list of builds, together with their current support lifecycle, is available. The Excel file also contains detailed fix lists. Download this Excel file now.

Note

Individual entries in the following table can be referenced directly through a bookmark. If you select any bug reference ID in the table, a bookmark tag is added to the URL by using the "#bkmk_NNNNNNN" format. You can then share this URL with others so that they can jump directly to the desired fix in the table.

Bug reference Description Fix area Component Platform
5383450 This fix addresses a vulnerability that affects the SQL Server managed backup to the Microsoft Azure stored procedures, managed_backup.sp_get_encryption_option and managed_backup.sp_do_backup. Customers who use managed backup should apply this update through the standard SQL Server servicing process. SQL Server Engine Backup Restore Linux;Windows
5442249 This fix addresses a security validation issue in SQL Server Agent if SQL Server Agent loads task-agent components. This fix strengthens security validation. SQL Server Engine SQL Agent Windows
5456059 This fix addresses reliability and security issues in SQL Server Agent if it processes specific input. SQL Server Engine SQL Agent Linux;Windows
5459644 This fix addresses an issue in which the SQL WMI Provider processes malformed input incorrectly while preserving existing behavior for valid input. SQL Server Engine WMI Management Provider (SqlMgmProvider) Windows
5462848 This fix addresses a security vulnerability in Microsoft Entra authentication login handling in SQL Server. SQL Server Engine Security Infrastructure Linux;Windows
5471638 This fix addresses validation of malformed Tabular Data Stream (TDS) and Binary XML input that's processed by SQL Server components. The input contains invalid length values that can cause unexpected behavior. SQL Connectivity SQL Connectivity Windows
5471844 This fix improves internal validation and security checks for SQL Server replication stored procedures to ensure that replication operations are processed by using the expected security safeguards. SQL Server Engine Replication Linux;Windows
5475810 This fix addresses input validation for parameters that are used by replication stored procedures to ensure that supplied values are processed reliably. SQL Server Engine Replication Linux;Windows
5481783 This fix addresses an issue that affects the security and reliability of SQL Server Agent under specific operating conditions. SQL Server Engine SQL Agent Linux;Windows
5484647 This fix addresses an issue in which a natively compiled stored procedure causes a heap buffer overwrite while streaming nvarchar(max) data that has SET TEXTSIZE truncation under a Variation Selector Sensitive (_VSS) collation. The issue causes the server to stop responding if the procedure uses small Tabular Data Stream (TDS) packet sizes. SQL Server Engine In-Memory OLTP Linux;Windows
5490417 This fix addresses an issue in which internal validation of backup metadata that's processed by the SQL Server Volume Shadow Copy Service (VSS) Writer improves handling of malformed or undersized metadata to ensure that it's rejected safely. SQL Server Engine Backup Restore Windows
5495728 This fix addresses an access violation that occurs if SQL Server processes a query that has an extremely large OPTION (USE PLAN) XML declaration. This access violation can cause the SQL Server process to terminate unexpectedly. SQL Server Engine XML Linux;Windows
5496503 This fix addresses a security issue in SQL Server by updating how SQL Server processes and outputs certain internal event data to help protect information. SQL Server Engine Programmability Linux;Windows
5499627 This fix addresses a security issue in SQL Server in which insufficient validation in Extended Events can cause memory corruption. SQL Server Engine Extended Events Linux;Windows
5499843 This fix addresses an XML data type handling bug in Document Type Definition (DTD) attribute lists. SQL Server Engine XML Linux;Windows
5499875 This fix addresses an integer overflow in the SQL Server XML reader that occurs if SQL Server processes a specially crafted XML format file through OPENROWSET(BULK...) or BULK INSERT. The integer overflow can cause the SQL Server process to stop responding or terminate unexpectedly. SQL Server Engine XML Linux;Windows
5500253 This fix resolves several security vulnerabilities that allow information disclosure or a denial of service if the database engine reads a specially crafted Extended Events (.xel) file. SQL Server Engine Extended Events Linux;Windows
5503317 This fix addresses an issue in which the SUBSTRING function reads beyond the allocated buffer if it processes malformed double-byte character set (DBCS) varchar input. The issue occurs in a natively compiled In-Memory Online Transaction Processing (OLTP) procedure. SQL Server Engine In-Memory OLTP Linux;Windows
5503319 This fix addresses an issue in which converting or truncating an NVARCHAR value that contains an Ideographic Variation Sequence (IVS) under a Variation Selector Sensitive (_VSS) collation causes an access violation. The issue occurs in a natively compiled In-Memory Online Transaction Processing (OLTP) procedure and causes the server to stop responding. SQL Server Engine In-Memory OLTP Linux;Windows
5506120 This fix addresses an improper input validation issue in SQL Server in which an authenticated user can provide a pointer that SQL Server dereferences and reads but does not execute. This issue can cause dump file generation or out-of-memory conditions. This fix strengthens input validation. SQL Server Engine Query Execution Linux;Windows
5533872 This update includes security and reliability improvements for the Queued Updating Subscriptions in Transactional Replication. SQL Server Engine Replication Windows
5533873 This update includes security and reliability improvements for the Queued Updating Subscriptions in Transactional Replication. SQL Server Engine Replication Windows
5541279 This fix improves the handling of input to Showplan to enhance security and reliability. SQL Server Engine Query Store Windows
5541728 This fix addresses improper field offset validation in the SqlDataRecord.SetBytes API for sql_variant values. This fix prevents an out-of-bounds heap write that can cause denial of service or elevation of privilege in SQL Server installations and Azure SQL Managed Instances that have common language runtime (CLR) enabled. SQL Server Engine Programmability Windows
5544180 This fix addresses an issue that affects the protection of internal replication data during processing operations. SQL Server Engine Replication Linux;Windows
5544245 This fix addresses an issue in Merge Replication that affects the handling of text data during processing operations. SQL Server Engine Replication Linux;Windows
5544588 This fix addresses an issue in replication operations that affects validation and handling to enhance security and reliability. SQL Server Engine Replication Linux;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 Windows Update: FAQ.

Method 2: Microsoft Update Catalog

To get the standalone package for this update, go to the Microsoft Update Catalog website.

Note

  • The detection logic has been updated for this and future security releases that are posted to the Microsoft Update Catalog website. For more information, see Updates to the Microsoft Update detection logic for SQL Server servicing.
  • This update is made available through the Microsoft Update Catalog for all servers that are running SQL Server, even if Reporting Services is not installed. Installing this security update is optional for computers that do not host Microsoft SQL Server Reporting Services.

Method 3: Microsoft Download Center

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

Download icon Download the package now

More information

Prerequisites

To apply this update, you must have SQL Server 2017 or any SQL Server 2017 CU release through this SQL Server 2017 CU31 GDR installed.

Security update deployment information

For deployment information about this update, see Deployments - Security Update Guide.

File hash information

File name SHA256 hash
SQLServer2017-KB5122774-x64.exe D0C78F50AC946D8F1BF5DC7FB8F18F84D55B838FEF17D8932C977333BD94143F

File information

The English version of this package has the file attributes (or later file attributes) that are listed in the following worksheet. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

For all supported x64-based versions - Download the list of files that are included in security update 5122774.

Information about protection and security

Protect yourself online: Windows Security support

Learn how we guard against cyber threats: Microsoft Security