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SQL Server 2017 CU31 + GDR SQL Server 2017 CU31 + GDR Security update
Patch Tuesday

KB5090354

KB5090354: Security update for SQL Server 2017, CU branch, May 2026. Web Service Task flaw could expose files or disrupt service

In short

Addresses an Important SQL Server remote code execution vulnerability and a Web Service Task XML flaw that could expose local files or cause a denial-of-service. Some linked server queries using MSDASQL still fail with error 7416.

Does it affect you? Applies to: Systems running SQL Server 2017, including x64-based systems. The update requires SQL Server 2017 or a CU release through CU31 GDR; installation is optional on computers that do not host SQL Server Reporting Services.

Build
14.0.3530.2
Servicing branch
CU
Security
1 fixed
Restart
Required

For servers on the CU branch: they install cumulative updates, which also bring fixes beyond security. Servers on the GDR branch (security fixes only) get a separate update. Which branch am I on?

What changes

Fix 1 change

Integration Services

For: SQL Server administrators using Integration Services

  • The Web Service Task's XML processing is protected against a flaw that could let an attacker read local files or cause a denial-of-service.1
    Addresses an XML external entity (XXE) vulnerability in the Web Service Task.

Known issues

  1. Open Affects: Organizations and IT administrators

    Linked server queries that use MSDASQL fail with error 7416

    Linked server queries using the MSDASQL provider and a provider string (@provstr) fail with error 7416, saying that access to the remote server is denied because no login mapping exists. A stricter Database Engine connection check can reject some configurations that worked in earlier builds.2

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2026-05-12
Classification
Security Updates
Type
Cumulative update
Servicing branch
CU
Restart
Required
Replaces
KB5084818, KB5077471, KB5068402, KB5065225
+7 earlier KB5063759, KB5058714, KB5050533, KB5046858, KB5046061, KB5042215, KB5040940
Replaced by
KB5102337
VersionBuildChannel
2017 14.0.3530.2 General availability

Security

1 vulnerability fixed
1 important
VulnerabilitySeverityCVSS
CVE-2026-40370
SQL Server Remote Code Execution Vulnerability
 Important 8.8

Downloads (Microsoft Update Catalog)

Package 2017
543.0 MB
sqlserver2017-kb5090354-x64.exe Main update · KB5090354 SHA-1: e912adb3…191558

Updated components

132 files changed since the previous update for the same versions.

Top changed componentsFiles
SQL Server Engine95
SQL Server PolyBase2

Sources

Updated
Cited passages from Microsoft's official notes (2)
  1. 1. This fix addresses an XML external entity (XXE) vulnerability in the Web Service Task that allows an attacker to read arbitrary files from the local file system or cause a denial-of-service (DoS) attack. support.microsoft.com
  2. 2. 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: support.microsoft.com
Checked automatically: 8 of 8 checks passed, 2 quoted passages · compared with Microsoft's page on Sep 26, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: passed

A second AI read the text against the sources: correctness 5/5, clarity 5/5, completeness 5/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake