KB5077181 — February 2026 Cumulative Update for Windows 11

Overview

KB5077181 is a comprehensive cumulative update released on February 10, 2026, for Windows 11 systems. This security-focused update addresses multiple critical vulnerabilities across core Windows components while delivering quality improvements to enhance system stability and performance. The update targets Windows 11 Version 24H2 and 25H2, updating them to builds 26100.7840 and 26200.7840 respectively.

Security Vulnerabilities Addressed

This update resolves several high-priority security vulnerabilities that could potentially compromise system security:

Kernel-Mode Vulnerabilities

Multiple elevation of privilege vulnerabilities in Windows kernel components have been patched. These vulnerabilities could allow attackers with limited user privileges to gain administrative access to affected systems. The fixes implement enhanced input validation and memory protection mechanisms to prevent exploitation.

Graphics Subsystem Vulnerabilities

Critical memory corruption issues in the Windows Graphics Device Interface have been resolved. These vulnerabilities could lead to arbitrary code execution through specially crafted graphics operations. The update includes improved bounds checking and memory allocation tracking to prevent buffer overflow conditions.

Authentication System Vulnerabilities

Authentication bypass vulnerabilities in Windows Local Security Authority have been corrected. These issues could allow unauthorized access to system resources by circumventing normal authentication processes. The fixes strengthen token validation and credential verification mechanisms.

Quality Improvements

Beyond security fixes, KB5077181 includes several quality improvements:

File System Reliability

NTFS file system corruption issues that could result in data loss have been addressed. The update improves metadata consistency checks and enhances error recovery procedures to maintain file system integrity.

Network Stack Stability

Denial of service vulnerabilities in the TCP/IP implementation have been resolved. These fixes prevent network-based attacks from causing system crashes or service disruptions.

Search Performance

Windows Search indexing performance has been optimized to reduce CPU usage and improve search result delivery times. The update includes algorithm improvements and better resource management.

Affected Systems

Installation Requirements

Before installing KB5077181, ensure your system meets the following requirements:

• Minimum 4 GB available disk space
• Active internet connection for Windows Update delivery
• Administrative privileges for manual installation
• No pending system restarts from previous updates

Deployment Considerations

Enterprise administrators should consider the following when deploying KB5077181:

Testing and Validation

Test the update in a controlled environment before broad deployment. Pay particular attention to applications that interact with graphics subsystems, authentication mechanisms, or network services.

Rollback Planning

While this update can be uninstalled if necessary, the security fixes it provides are critical. Plan rollback procedures only for systems experiencing compatibility issues.

Communication

Inform users about the required restart and any temporary service disruptions during installation. The update process typically takes 15-30 minutes depending on system configuration.

Post-Installation Verification

After installing KB5077181, verify the update was applied successfully:

Get-HotFix -Id KB5077181

Check the system build number:

Get-ComputerInfo | Select-Object WindowsVersion, WindowsBuildLabEx

The build number should reflect 26100.7840 for Windows 11 24H2 or 26200.7840 for Windows 11 25H2.