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SQL Server 2019 GDR SQL Server 2019 GDR Security update
Patch Tuesday

KB5128495

KB5128495: Security update for SQL Server 2019, GDR branch, October 2026. 21 vulnerabilities fixed; MSDASQL linked queries can fail

In short

The update fixes 21 vulnerabilities in SQL Server 2019 GDR. A known issue can make linked server queries using MSDASQL and a provider string fail with error 7416.

Does it affect you? Applies to: SQL Server 2019 installations on supported x64 systems that have SQL Server 2019 GDR or a later GDR release installed. The fixes table lists Linux and Windows platforms where applicable.

Build
15.0.2200.2
Servicing branch
GDR
Security
21 fixed
Restart
Required

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

What changes

Fixes 12 changes

PolyBase

2 items
  • PolyBase gets improved data-processing validation to address a security vulnerability.1
    Improves validation during data processing to resolve a security vulnerability in PolyBase.
  • PolyBase rejects malformed rollback queue data.7
    Fixes unsafe deserialization of PolyBase rollback queue data.

Extensibility

For: SQL Server administrators using Machine Learning Services or Language Extensions

  • Fixes memory-corruption and memory-disclosure vulnerabilities in message processing used by Machine Learning Services and Language Extensions.2
    Fixes vulnerabilities in SQL Satellite protocol message parsing logic.

Backup Restore

4 items

For: SQL Server administrators on Windows

  • Malformed size values in backup paths are rejected before they can cause unsafe memory access.3
    Hardens arithmetic and transfer-size validation in SQL Server Virtual Device Interface (VDI) and SQL Writer backup paths.
  • Malformed or oversized backup and restore metadata is rejected before memory operations, addressing a risk of elevated privileges or a stalled service.4
    Adds strict bounds validation and safe size calculation checks to backup and restore metadata processing.
  • Fixes a security vulnerability that could allow an out-of-bounds write while opening a virtual device set.5
    Fixes an out-of-bounds write vulnerability in the SQL Server Virtual Device Interface (VDI).
  • Fixes a security vulnerability that could allow an out-of-bounds read or write while processing transferred data during backup or restore.6
    Fixes an out-of-bounds read or write vulnerability in the SQL Server Virtual Device Interface (VDI).

Distributed Query

For: SQL Server administrators using MSDASQL linked servers

  • MSDASQL linked server connections work when the provider string does not include a user ID.8
    Fixes MSDASQL-linked server connection failures when the provider string omits UID.

Replication

2 items
  • A data-validation issue in replication operations is fixed.9
    Fixes an issue affecting data validation in replication operations.
  • A data-validation issue in merge replication Web Synchronization operations is fixed.10
    Fixes an issue affecting data validation in merge replication Web Synchronization operations.

Programmability

For: SQL Server administrators on Windows

  • Malformed trace data cannot make LoginSid processing in the SQL Trace reader read beyond its internal buffer.11
    Limits LoginSid processing within the SQL Trace reader to the internal buffer size to prevent an out-of-bounds read from malformed trace data.

Extended Events

  • Fixes vulnerabilities that could expose information or cause a denial of service when the Database Engine reads a specially crafted Extended Events file.12
    Fixes vulnerabilities involving specially crafted .xel files.

Improvements 10 changes

Extensibility

For: SQL Server administrators with external language or library packages

  • Package extraction uses an updated third-party component when external language or external library packages are installed.13
    Updates the third-party archive-extraction component used by SQL Server for external language and external library packages.

High Availability and Disaster Recovery

For: SQL Server administrators using Availability Groups

  • Availability Group secondary replicas reject oversized FILESTREAM fragments.14
    Adds validation of FILESTREAM fragment size on Availability Group secondary replicas.

Replication

5 items
  • Queued Updating Subscriptions get security and reliability improvements.15
    Improves security and reliability for Queued Updating Subscriptions in Transactional Replication.
  • Queued Updating Subscriptions get security and reliability improvements.16
    Improves security and reliability for Queued Updating Subscriptions in Transactional Replication.
  • Authorization checks help prevent unintended disclosure of database information during certain replication-related operations.20
    Strengthens authorization checks for certain replication-related database operations.
  • Replication security metadata handling gets security and reliability improvements during Subscriber database restore and upgrade.21
    Improves replication security metadata handling during Subscriber database restore and upgrade operations.
  • The Log Reader Agent gets security and reliability improvements in heterogeneous transactional replication scenarios.22
    Improves the Log Reader Agent for heterogeneous transactional replication.

Query Store

For: SQL Server administrators on Windows

  • Showplan input handling gets security and reliability improvements.17
    Improves Showplan input handling.

PolyBase

2 items
  • PolyBase shared memory handling is updated.18
    Updates shared memory handling.
  • PolyBase Native Compare Strings is updated.19
    Updates Native Compare Strings.

Known issues

  1. Open Affects: Organizations and IT administrators

    Linked server queries that use MSDASQL fail with error 7416

    Linked server queries that use MSDASQL and specify a provider string might fail with error 7416, stating that no login mapping exists.23

    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
2026-10-13
Classification
Security Updates
Type
Cumulative update
Servicing branch
GDR
Restart
Required
Replaces
KB5122773, KB5102336, KB5090408, KB5084817
+10 earlier KB5077470, KB5068405, KB5065223, KB5063758, KB5058713, KB5046859, KB5046056, KB5042214, KB5040986, KB5035434
Replaced by
KB5132751
VersionBuildChannel
2019 15.0.2200.2 General availability

Security

21 vulnerabilities fixed
16 important 5 not rated
VulnerabilitySeverityCVSS
CVE-2026-65674
Microsoft SQL Server Remote Code Execution Vulnerability
 Important 8.8
CVE-2026-67625
Microsoft SQL Server Remote Code Execution Vulnerability
 Important 8.5
CVE-2026-68883
Microsoft SQL Server Elevation of Privilege Vulnerability
 Important 8.5
CVE-2026-85886
Microsoft SQL Server Remote Code Execution Vulnerability
 Important 8.5
CVE-2026-85888
Microsoft SQL Server Information Disclosure Vulnerability
 Important 7.7
CVE-2026-88081
Microsoft SQL Server Information Disclosure Vulnerability
 Important 7.7
CVE-2026-85876
Microsoft SQL Server Elevation of Privilege Vulnerability
 Important 7.0
CVE-2026-85919
Microsoft SQL Server Elevation of Privilege Vulnerability
 Important 7.0
CVE-2026-88082
Microsoft SQL Server Elevation of Privilege Vulnerability
 Important 7.0
CVE-2026-88088
Microsoft SQL Server Elevation of Privilege Vulnerability
 Important 7.0
CVE-2026-32176
SQL Server Elevation of Privilege Vulnerability
 Important 6.7
CVE-2026-70189
Microsoft SQL Server Remote Code Execution Vulnerability
 Important 6.7
CVE-2026-88085
Microsoft SQL Server Elevation of Privilege Vulnerability
 Important 6.4
CVE-2026-88084
Microsoft SQL Server Denial of Service Vulnerability
 Important 5.3
CVE-2026-88086
Microsoft SQL Server Information Disclosure Vulnerability
 Important 5.3
CVE-2026-67628
Microsoft SQL Server Information Disclosure Vulnerability
 Important 4.9
CVE-2026-83945
Microsoft SQL Server Remote Code Execution Vulnerability
 Not rated —
CVE-2026-88089
Microsoft SQL Server Remote Code Execution Vulnerability
 Not rated —
CVE-2026-94512
SQL Server Remote Code Execution Vulnerability
 Not rated —
CVE-2026-94520
Microsoft SQL Server Denial of Service Vulnerability
 Not rated —
CVE-2026-96956
SQL Server Elevation of Privilege Vulnerability
 Not rated —

Downloads (Microsoft Update Catalog)

Package 2019
511.3 MB
sqlserver2019-kb5128495-x64.exe Main update · KB5128495 SHA-1: ae3fb83d…75ee23

Updated components

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

Top changed componentsFiles
SQL Server Engine121
SQL Server PolyBase5

Page history

  1. Superseded by KB5132751

    Removed CVE-2026-88089

    Removed CVE-2026-94512

    Removed CVE-2026-94520

    Removed CVE-2026-96956

Sources

Updated
Cited passages from Microsoft's official notes (23)
  1. 1. Resolves a security vulnerability in PolyBase by improving validation during data processing. support.microsoft.com
  2. 2. Fix multiple memory-corruption and memory-disclosure vulnerabilities in SQL Server's SQL Satellite protocol message parsing logic used by Machine Learning Services and Language Extensions. support.microsoft.com
  3. 3. Addresses an input-validation issue in SQL Server Virtual Device Interface (VDI) and SQL Writer backup paths in which malformed size values potentially cause out-of-bounds memory access. support.microsoft.com
  4. 4. Addresses an integer handling issue in SQL Server backup and restore metadata processing that potentially allows a local authenticated user to gain elevated privileges and cause a service to stop responding. support.microsoft.com
  5. 5. Fixes a security vulnerability in the SQL Server Virtual Device Interface (VDI) in which an out-of-bounds write action potentially occurs while opening a virtual device set. support.microsoft.com
  6. 6. Fixes a security vulnerability in the SQL Server Virtual Device Interface (VDI) in which an out-of-bounds read or write actions potentially occur while processing transferred data during backup or restore operations. support.microsoft.com
  7. 7. Fixes unsafe deserialization of PolyBase rollback queue data so that malformed payloads are rejected. support.microsoft.com
  8. 8. Fixes an issue in which MSDASQL-linked server connections fail if the provider string doesn't include a user ID (UID). support.microsoft.com
  9. 9. Fixes an issue in replication operations that affects data validation. support.microsoft.com
  10. 10. Fixes an issue in merge replication Web Synchronization operations that affects data validation. support.microsoft.com
  11. 11. Limits LoginSid processing within the SQL Trace reader to the internal buffer size to prevent malformed trace data from causing an out-of-bounds read action. support.microsoft.com
  12. 12. Fixes several security vulnerabilities that allow information disclosure or a denial of service when the Database Engine reads a specially crafted Extended Events (.xel) file. support.microsoft.com
  13. 13. Updates the third-party archive-extraction component that SQL Server uses if external language and external library packages are installed. support.microsoft.com
  14. 14. Adds validation of FILESTREAM fragment size on Availability Group secondary replicas to reject oversized fragments. support.microsoft.com
  15. 15. Improves security and reliability for Queued Updating Subscriptions in Transactional Replication. support.microsoft.com
  16. 16. Improves security and reliability for Queued Updating Subscriptions in Transactional Replication. support.microsoft.com
  17. 17. Improves Showplan input handling to enhance security and reliability. support.microsoft.com
  18. 18. Updates shared memory handling. support.microsoft.com
  19. 19. Updates Native Compare Strings. support.microsoft.com
  20. 20. Strengthens authorization checks for certain replication-related database operations to help prevent unintended disclosure of database information. support.microsoft.com
  21. 21. Improves security and reliability in replication security metadata handling during Subscriber database restore and upgrade operations. support.microsoft.com
  22. 22. Improves security and reliability for the Log Reader Agent in a heterogeneous transactional replication scenario. support.microsoft.com
  23. 23. 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: 7 of 8 checks passed, 23 quoted passages · compared with Microsoft's page on Nov 14, 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: not passed

A second AI read the text against the sources: correctness 4/5, clarity 4/5, 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