KB5078938 — March 2026 Security Update for Windows 10 Version 1607 and Windows Server 2016

Overview

KB5078938 is a critical security update released on March 10, 2026, for Windows 10 Version 1607 and Windows Server 2016 systems. This update addresses multiple high-priority security vulnerabilities and updates the operating system build to 14393.8957. The update is part of Microsoft's regular Patch Tuesday release cycle and includes fixes for vulnerabilities that could potentially be exploited by attackers to compromise system security.

Security Vulnerabilities Addressed

This update resolves several categories of security vulnerabilities that affect core Windows components:

Kernel Privilege Escalation

Multiple vulnerabilities in the Windows kernel could allow local attackers to escalate privileges from standard user to SYSTEM level. These vulnerabilities stem from improper validation of user input in kernel-mode drivers and insufficient access controls for certain system operations. Successful exploitation could allow attackers to install programs, view and modify data, or create new accounts with full user rights.

Remote Code Execution in Networking Stack

Critical vulnerabilities in Windows networking components could allow remote attackers to execute arbitrary code on vulnerable systems. These vulnerabilities affect the processing of specially crafted network packets and could be exploited without user interaction. Successful exploitation could result in complete system compromise.

Authentication Bypass

Vulnerabilities in Windows authentication mechanisms could allow attackers to bypass authentication requirements and gain unauthorized access to system resources. These issues affect both local and network authentication scenarios and could be exploited to access sensitive data or system functions.

Information Disclosure

Several vulnerabilities could allow unauthorized disclosure of sensitive system information, including memory contents, system configuration details, and user data. While these vulnerabilities may not directly compromise system integrity, they could provide attackers with information useful for further attacks.

Denial of Service

Multiple vulnerabilities could be exploited to cause system crashes or unresponsive conditions, potentially disrupting business operations or system availability.

Affected Systems

This update applies to the following operating systems and editions:

Installation Process

The installation process varies depending on the deployment method chosen:

Automatic Installation via Windows Update

For most users, KB5078938 will be automatically downloaded and installed through Windows Update. The process includes:

1. Automatic detection of update availability
2. Background download of update packages
3. Installation during next maintenance window or manual restart
4. System restart to complete installation
5. Post-installation configuration and optimization

Manual Installation

Administrators can manually install the update using the following methods:

• Windows Update Settings: Navigate to Settings > Update & Security > Windows Update and select "Check for updates"
• Microsoft Update Catalog: Download the appropriate package and install using wusa.exe or Windows Update Standalone Installer
• Command Line: Use dism.exe or wusa.exe with appropriate parameters for silent installation

Enterprise Deployment

Enterprise environments can deploy this update through established update management systems:

• WSUS: Approve the update for deployment to target computer groups
• SCCM: Create software update deployments with appropriate scheduling and requirements
• Group Policy: Configure automatic update policies to ensure timely deployment

Post-Installation Verification

After installation, verify the update was applied successfully:

Get-HotFix -Id KB5078938

Check the system build number:

Get-ComputerInfo | Select-Object WindowsVersion, WindowsBuildLabEx

The build number should show 14393.8957 after successful installation.

Security Recommendations

Microsoft recommends the following security best practices in conjunction with installing this update:

• Ensure all systems receive regular security updates through automated update mechanisms
• Implement defense-in-depth security strategies including network segmentation and access controls
• Monitor systems for unusual activity that could indicate compromise
• Maintain current antivirus and anti-malware solutions
• Regularly review and update security policies and procedures