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KB5081495 - Cumulative Update 4 for SQL Server 2025

  • Applies to: SQL Server 2025 on Windows, SQL Server 2025 on Linux

Release Date:   April 16, 2026
Version:   17.0.4035.5

Summary

This article describes Cumulative Update (CU4) for Microsoft SQL Server 2025. This update package contains 11 fixes that were issued after the release of SQL Server 2025 Cumulative Update 3. It updates components in the following builds:

  • SQL Server - Product version: 17.0.4035.5, file version: 2025.170.4035.5
  • Analysis Services - Product version: 17.0.25.223, file version: 2025.170.25.223

Known issues in this update

Incorrect behavior of SESSION_CONTEXT in parallel plans

Queries that use the built-in SESSION_CONTEXT function might return incorrect results or trigger access violation (AV) dump files when run in parallel query plans. This issue occurs because of the manner in which SESSION_CONTEXT interacts with parallel execution threads, particularly if the session is reset for reuse.

For more information, see the Known issues section in SESSION_CONTEXT.

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 for SQL Server 2025, SQL Server 2022, SQL Server 2019, and SQL Server 2017. 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 "#NNNNNNN" format. You can then share this URL with others so that they can jump directly to the desired fix in the table.

For more information about the bugs that are fixed and enhancements that are included in this cumulative update, see the following table.

Bug Reference Description Fix Area Component Platform
4954486 Fixes an issue in contained availability groups that causes DatabaseMail to sends email messages without attachments when using sp_RunMailQuery. SQL Server Client Tools Database Mail All
5000227 Fixes an issue in which permissions on stored procedures and other objects in msdb are lost during the SQL Server upgrade process. This issue causes unexpected permission removal for users. SQL Server Engine Management Services Windows
5001765 Fixes an issue in which the server could enter an unintended wait state on an internal thread that does not support suspension. This issue potentially causes the program to stop responding. The lock is now acquired by using a spin-wait on such threads instead of blocking. SQL Server on Linux SQLPAL Linux
5003709 Fixes an issue in which DTSWizard.exe doesn't open if SQL Server is installed without the SQL Server Integration Services (SSIS) features. Integration Services Integration Services Windows
5008479 Fixes an issue in which indexing certain Microsoft Word 6.0 documents by including Full-Text Search causes the filter daemon host process (fdhost.exe) to stop responding. SQL Server Engine Search All
5019346 Fixes a memory corruption issue in the audit functionality for contained availability groups. SQL Server Engine High Availability and Disaster Recovery All
5028791 Fixes an access violation error that occurs when you query sys.dm_xe_session_targets for instances that run on Windows Server 2025. SQL Server Engine SQL OS Windows
5029490 Limits the comparison mode for Json_contains to a value of either 0 (exact match) or 1 (pattern match). The default value is 0. SQL Server Engine JSON All
5033606 For contained availability groups (CAG), restricts adding databases to only the currently connected CAG. For DBCreator, restricts adding databases to only the current CAG, and requires the database owner to match the logged-in user. SQL Server Engine High Availability and Disaster Recovery All
5063278 Fixes non-yielding scheduler errors and dump files that might occur during a high amount of lazy writer I/O. SQL Server Engine Replication All
5071334 Fixes an issue in which inflectional Full-Text Search queries fail for version 2 languages that do not implement an IStemmer. This issue generates error messages that include predicates such as FREETEXT, FREETEXTTABLE, and FORMSOF(INFLECTIONAL, ...). SQL Server Engine Search All

How to obtain or download this CU or the latest CU package

How to obtain or download the latest cumulative update package for Windows (recommended)

The following update is available from the Microsoft Download Center:

Download the latest cumulative update package for SQL Server 2025 now

Note

  • Microsoft Download Center always offers the latest SQL Server 2025 CU release.
  • If the download page doesn't appear, contact Microsoft Customer Service and Support to obtain the cumulative update package.
How to obtain or download this cumulative update package for Windows from Microsoft Update Catalog

The following update is available from the Microsoft Update Catalog:

Note

  • Microsoft Update Catalog contains this SQL Server 2025 CU and previously released SQL Server 2025 CU releases.
  • This CU is also available through Windows Server Update Services (WSUS).
  • We recommend that you always install the latest cumulative update that's available.
How to obtain or download the latest cumulative update package for Linux

To update SQL Server 2025 on Linux to the latest CU, you must first have the Cumulative Update repository configured. Then, update your SQL Server packages by using the appropriate platform-specific update command.

For installation instructions and direct links to the CU package downloads, see the SQL Server 2025 Release Notes.

File information

File hash information

You can verify the download by computing the hash of the SQLServer2025-KB5081495-x64.exe file through the following command:

certutil -hashfile SQLServer2025-KB5081495-x64.exe SHA256

File name SHA256 hash
SQLServer2025-KB5081495-x64.exe E8050B7619939C6C0F2CA352DA50F8659F0BEFD63798A4EDC84210F084EA199B
Cumulative Update package file information

Download the list of files that are included in KB5081495.

Notes for this update

Prerequisites

To apply this cumulative update package, you must be running SQL Server 2025.

Restart information

You might have to restart the computer after you apply this cumulative update package.

Registry information

To use one of the hotfixes in this package, you don't have to make any changes to the registry.

Important notices

This article also provides the following important information.

Analysis Services CU build version

Beginning in Microsoft SQL Server 2017, the Analysis Services build version number and SQL Server Database Engine build version number don't match. For more information, see Verify Analysis Services cumulative update build version.

Cumulative updates (CU)

  • Each new CU contains all the fixes that were included with the previous CU for the installed version of SQL Server.
  • SQL Server CUs are certified to the same levels as service packs, and should be installed at the same level of confidence.
  • We recommend ongoing, proactive installation of CUs as they become available according to these guidelines:
    • Historical data shows that a significant number of support cases involve an issue that was already addressed in a released CU.
    • CUs might contain added value over and above hotfixes, such as supportability, manageability, and reliability updates.
  • We recommend that you test SQL Server CUs before you deploy them to production environments.
Hybrid environment deployment

When you deploy an update to a hybrid environment (such as Always On, replication, cluster, and mirroring), we recommend that you refer to the following articles before you deploy the update:

Language support

SQL Server CUs are currently multilingual. Therefore, this CU package isn't specific to one language. It applies to all supported languages.

Components (features) updated

One CU package includes all available updates for all SQL Server 2025 components (features). However, the cumulative update package updates only those components that are currently installed on the SQL Server instance that you select to be serviced. If a SQL Server feature (for example, Analysis Services) is added to the instance after this CU is applied, you must reapply this CU to update the new feature to this CU.

Support for this update

If other issues occur, or if any troubleshooting is required, you might have to create a service request. The usual support costs will apply to additional support questions and to issues that don't qualify for this specific cumulative update package. For a complete list of Microsoft Customer Service and Support telephone numbers, or to create a separate service request, go to the Microsoft support website.

How to uninstall this update

How to uninstall this update on Windows
  1. In Control Panel, open the Programs and Features item, and then select View installed updates.
  2. Locate the entry that corresponds to this cumulative update package under SQL Server 2025.
  3. Press and hold (or right-click) the entry, and then select Uninstall.
How to uninstall this update on Linux

To uninstall this CU on Linux, you must roll back the package to the previous version. For more information about how to roll back the installation, see Rollback SQL Server.

References

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