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SQL Server 2022 CU23 + GDR SQL Server 2022 CU23 + GDR Security update
Patch Tuesday

KB5077464

KB5077464: Security update for SQL Server 2022, CU branch, March 2026. Merge replication upgrade flaw fixed; ALTER USER restricted

In short

Fixes two Important vulnerabilities, including publicly disclosed CVE-2026-21262, and blocks ALTER USER when its target is the system Administrator account.

Does it affect you? Applies to: SQL Server 2022 instances on Windows or Linux that meet the update prerequisites. The security update is optional on computers that do not host Microsoft SQL Server Reporting Services.

Build
16.0.4240.4
Servicing branch
CU
Security
2 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

Fixes 2 changes

Replication

For: SQL Server instances using merge replication

  • Fixes an elevation-of-privilege flaw in the merge replication version upgrade process.1
    The fix applies to Windows.

Security Infrastructure

  • ALTER USER is blocked when the target login is the system Administrator account.2
    The fix applies to Linux and Windows.

Technical details

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

Data sheet

Released
2026-03-10
Classification
Security Updates
Type
Cumulative update
Servicing branch
CU
Restart
Required
Replaces
KB5078297, KB5072936, KB5068450, KB5068406
+20 earlier KB5065865, KB5065220, KB5063814, KB5059390, KB5058721, KB5054531, KB5050771, KB5048038, KB5048033, KB5046862, KB5046059, KB5041321, KB5042578, KB5038325, KB5040939, KB5036432, KB5036343, KB5033663, KB5032679, KB5033592
Replaced by
KB5083252
VersionBuildChannel
2022 16.0.4240.4 General availability

Security

2 vulnerabilities fixed
2 important
VulnerabilitySeverityCVSS
CVE-2026-21262
Microsoft SQL Server Elevation of Privilege Vulnerability
 Important 8.8
CVE-2026-26115
SQL Server Elevation of Privilege Vulnerability
 Important 8.8

Downloads (Microsoft Update Catalog)

Package 2022
464.4 MB
sqlserver2022-kb5077464-x64.exe Main update · KB5077464 SHA-1: 6ac4eee9…e0bc79

Updated components

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

Top changed componentsFiles
SQL Server Engine115
SQL Server PolyBase2

Sources

Updated
Cited passages from Microsoft's official notes (2)
  1. 1. Fixes an elevation of privilege vulnerability in the version upgrade process for merge replication. support.microsoft.com
  2. 2. This hotfix blocks the ALTER USER operation if the target login is the system Administrator account. 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 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