KB5077472 — Security Update for SQL Server 2017 GDR

Overview

KB5077472 is a critical security update released on March 10, 2026, for Microsoft SQL Server 2017 GDR (General Distribution Release). This update addresses multiple high-severity security vulnerabilities in the SQL Server Database Engine that could potentially allow remote code execution, information disclosure, denial of service attacks, and authentication bypass.

The update is specifically designed for x64-based systems running SQL Server 2017 GDR and includes comprehensive security enhancements to protect database environments from emerging security threats. Organizations running SQL Server 2017 in production environments should prioritize the installation of this security update.

Security Vulnerabilities Addressed

This security update resolves four critical vulnerabilities identified in SQL Server 2017:

CVE-2026-0847: Remote Code Execution in Database Engine

A critical vulnerability in the SQL Server Database Engine could allow an authenticated attacker to execute arbitrary code with elevated privileges. The vulnerability exists in query processing routines where improper input validation could lead to buffer overflow conditions. Successful exploitation could result in complete system compromise.

CVE-2026-0848: Information Disclosure in Query Execution

An information disclosure vulnerability in query execution mechanisms could allow attackers to access sensitive data from other database sessions or system memory. The vulnerability occurs when specially crafted queries bypass normal isolation mechanisms, potentially exposing confidential information.

CVE-2026-0849: Denial of Service in Connection Handling

A denial of service vulnerability in SQL Server's connection handling could be exploited to cause service interruption or complete service failure. Malformed connection requests could trigger resource exhaustion or service crashes, affecting database availability.

CVE-2026-0850: Authentication Bypass

Authentication bypass vulnerabilities in specific SQL Server configurations could allow unauthorized database access. The vulnerabilities affect authentication validation mechanisms and could be exploited to gain unauthorized access to database resources.

Affected Systems

This security update applies to the following SQL Server 2017 configurations:

Installation Process

The installation process for KB5077472 varies depending on your deployment method:

Standalone Installation

For individual SQL Server instances, download the update package from Microsoft Update Catalog and run the installation with administrative privileges:

SQLServer2017-KB5077472-x64.exe /quiet /IAcceptSQLServerLicenseTerms

Enterprise Deployment

Enterprise environments should use centralized deployment methods:

• WSUS: Approve the update in the SQL Server product category
• SCCM: Deploy through software update management with custom deployment schedules
• PowerShell DSC: Integrate into desired state configuration for automated deployment

Verification Commands

Verify successful installation using SQL Server Management Studio or T-SQL commands:

SELECT @@VERSION;
SELECT * FROM sys.dm_os_windows_info;

Post-Installation Considerations

After installing KB5077472, administrators should:

• Monitor SQL Server error logs for any unusual activity or warnings
• Verify database connectivity and application functionality
• Update database statistics if performance issues are observed
• Review security configurations to ensure optimal protection
• Test backup and recovery procedures to ensure continued functionality

Security Best Practices

In addition to installing this security update, organizations should implement comprehensive security measures:

• Regular security assessments and vulnerability scanning
• Implementation of least privilege access principles
• Network segmentation and firewall configuration
• Regular backup and disaster recovery testing
• Monitoring and logging of database access and activities