KB5082060 — April 2026 Security Update for Windows Server 2022 23H2

Overview

KB5082060 is a critical security update released on April 14, 2026, for Windows Server 2022 23H2 Edition. This update addresses five significant security vulnerabilities and updates the operating system build to 25398.2274. The update applies to both Server Core and Desktop Experience installations and is essential for maintaining security compliance in enterprise environments.

Security Vulnerabilities Addressed

This update resolves multiple high-priority security issues:

Kernel Privilege Escalation (CVE-2026-0847)

A critical vulnerability in the Windows kernel allows local attackers to escalate privileges to SYSTEM level through improper validation of kernel driver interfaces. This vulnerability has a CVSS score of 7.8 and affects all Windows Server 2022 23H2 installations. The fix implements additional validation checks and strengthens memory protection mechanisms in ntoskrnl.exe.

Windows Defender Application Control Bypass (CVE-2026-0851)

This security feature bypass vulnerability allows attackers to execute unsigned code despite WDAC policies. The vulnerability affects environments relying on application control for security compliance. The update strengthens code integrity verification in ci.dll and closes policy enforcement loopholes.

Remote Desktop Services Denial of Service (CVE-2026-0855)

A vulnerability in Remote Desktop Services could be exploited to cause system crashes or service unavailability. This particularly affects servers with RDS roles enabled in enterprise environments. The fix improves input validation and resource management in terminal services components.

Schannel Certificate Validation (CVE-2026-0859)

Improper certificate chain validation in the Secure Channel security package could allow man-in-the-middle attacks against TLS/SSL connections. This affects all server applications using Schannel for secure communications. The update enhances certificate verification logic and improves connection security.

Print Spooler Privilege Escalation (CVE-2026-0863)

Multiple vulnerabilities in the Windows Print Spooler service allow local privilege escalation through improper file handling and access controls. The fix implements stricter security measures in spoolsv.exe and print driver interfaces.

Technical Implementation

The update modifies several core Windows components:

• Kernel Components: ntoskrnl.exe, kernel drivers, and memory management subsystems
• Security Components: ci.dll, schannel.dll, and Windows Defender Application Control
• Network Services: termdd.sys, rdpcorets.dll, and Remote Desktop Services
• Print Services: spoolsv.exe, print drivers, and spooler subsystem

Deployment Considerations

Enterprise administrators should consider the following deployment strategies:

Phased Deployment

Deploy the update in phases, starting with non-critical servers to identify potential issues before updating production systems. Allow 24-48 hours between phases to monitor for issues.

Maintenance Windows

Schedule installation during planned maintenance windows due to the required restart. The installation process typically takes 15-30 minutes plus restart time.

Testing Requirements

Test the update in representative environments, particularly focusing on:

• Print services functionality
• Remote Desktop Services connectivity
• Application compatibility with WDAC policies
• TLS/SSL certificate validation

Compliance and Security Impact

This update is critical for maintaining security compliance in enterprise environments. Organizations should prioritize installation within 30 days of release to address the identified vulnerabilities. The update aligns with current security frameworks and compliance requirements for Windows Server environments.

Post-Installation Verification

After installation, verify the update was applied successfully:

Get-HotFix -Id KB5082060
Get-ComputerInfo | Select-Object WindowsVersion, WindowsBuildLabEx

The build number should show 25398.2274 after successful installation and restart.