KB5089900 — Security Update for SQL Server 2022 CU24

Overview

KB5089900 is a critical security update released on May 12, 2026, for Microsoft SQL Server 2022 Cumulative Update 24. This update addresses multiple high-severity vulnerabilities that could allow privilege escalation, remote code execution, information disclosure, and denial of service attacks against SQL Server instances running on x64-based systems.

Security Vulnerabilities Addressed

This security update resolves four critical vulnerabilities identified in SQL Server 2022 CU24:

CVE-2026-0234: SQL Server Privilege Escalation

A privilege escalation vulnerability exists in the SQL Server Database Engine that allows authenticated users to gain elevated permissions beyond their assigned roles. This vulnerability affects all SQL Server 2022 editions and could allow attackers with basic database access to obtain administrative privileges.

CVE-2026-0235: Analysis Services Remote Code Execution

A remote code execution vulnerability in SQL Server Analysis Services allows attackers to execute arbitrary code on the server through specially crafted MDX or DAX queries. This vulnerability poses a critical risk to systems running Analysis Services components.

CVE-2026-0236: Reporting Services Information Disclosure

An information disclosure vulnerability in SQL Server Reporting Services could allow unauthorized access to sensitive data through improper report rendering. This affects environments using Reporting Services for business intelligence and reporting functions.

CVE-2026-0237: Database Engine Denial of Service

A denial of service vulnerability in the SQL Server Database Engine could cause service disruption through malformed query processing. This vulnerability could impact database availability and performance.

Affected Systems

This security update applies to the following Microsoft SQL Server configurations:

Operating System Compatibility

The update is compatible with the following Windows Server operating systems:

• Windows Server 2019 (all editions)
• Windows Server 2022 (all editions)
• Windows Server 2025 (all editions)
• Windows 11 (for development and testing scenarios)
• Windows 10 (for development and testing scenarios)

Installation Process

Before installing KB5089900, ensure that your system meets the following prerequisites:

Pre-Installation Steps

1. Verify that SQL Server 2022 CU24 is installed by running:

   SELECT @@VERSION

2. Create a full backup of all critical databases
3. Stop all SQL Server services using SQL Server Configuration Manager
4. Ensure sufficient disk space (minimum 1 GB free on system drive)
5. Close all SQL Server Management Studio and client connections

Installation Methods

Manual Installation

1. Download KB5089900 from Microsoft Update Catalog
2. Run the installer with administrator privileges
3. Follow the installation wizard prompts
4. Restart the system when prompted
5. Verify installation success using

   Get-HotFix -Id KB5089900

Enterprise Deployment

For enterprise environments, deploy through WSUS or SCCM by approving the update for SQL Server 2022 systems. Configure deployment schedules to minimize impact on production databases during business hours.

Post-Installation Verification

After installing KB5089900, perform the following verification steps:

1. Confirm SQL Server services start successfully
2. Verify database connectivity using SQL Server Management Studio
3. Check Windows Event Log for any SQL Server-related errors
4. Test critical database applications and queries
5. Validate Analysis Services and Reporting Services functionality if applicable

Build Number Verification

After successful installation, the SQL Server build number should be updated to 16.0.4135.7. Verify this by executing:

SELECT SERVERPROPERTY('ProductVersion') AS Version, SERVERPROPERTY('ProductLevel') AS Level

Security Impact Assessment

Organizations should prioritize the installation of KB5089900 due to the critical nature of the addressed vulnerabilities. The privilege escalation and remote code execution vulnerabilities pose significant security risks that could lead to complete system compromise.

Risk Mitigation

Until this update can be installed, consider implementing the following temporary mitigations:

• Restrict network access to SQL Server instances using firewalls
• Review and minimize user permissions and role assignments
• Monitor SQL Server logs for suspicious activity
• Disable unnecessary SQL Server features and services
• Implement network segmentation for database servers

Compatibility and Performance

This security update maintains full compatibility with existing SQL Server 2022 applications and configurations. No breaking changes are introduced that would affect application functionality or database schema.

Performance testing indicates minimal impact on database operations, with enhanced security validation adding less than 2% overhead to query processing times. The security improvements provide substantial protection benefits that outweigh the minimal performance impact.