KB5077796 is an out-of-band cumulative update released on January 17, 2026, for Windows 10 systems. This update addresses critical security vulnerabilities and resolves system stability issues affecting Windows 10 Version 21H2 and 22H2, updating systems to builds 19044.6811 and 19045.6811 respectively.
Knowledge BaseKB5077796Windows 10
KB5077796 — Out-of-band Update for Windows 10 Version 21H2 and 22H2
KB5077796 is an out-of-band cumulative update released January 17, 2026, addressing critical security vulnerabilities and system stability issues in Windows 10 Version 21H2 and 22H2.
Evan Mael KB5077796Windows 10Cumulative Update 5 fixes 12 min Windows 10 Version 21H2 (Build 19044) +1Download
Quick Overview
PowerShell—Check if KB5077796 is installed
PS C:\> Get-HotFix -Id KB5077796# Returns patch details if KB5077796 is installed
Download Update
Download from Microsoft Update Catalog
Get the official update package directly from Microsoft
Diagnostic
Issue Description
Issue Description
This out-of-band update addresses several critical issues affecting Windows 10 systems:
- System crashes and blue screen errors (BSOD) during startup or normal operation
- Security vulnerabilities that could allow unauthorized access to system resources
- Performance degradation in certain system components
- Compatibility issues with specific hardware configurations
- Network connectivity problems in enterprise environments
- Windows Update service failures preventing automatic updates
Users may experience unexpected system restarts, application crashes, or reduced system performance before applying this update.
Analysis
Root Causes
Root Cause
The issues addressed by KB5077796 stem from multiple system components including kernel-level drivers, security subsystems, and core Windows services. Security vulnerabilities were identified in the Windows kernel and related system processes that could potentially be exploited by malicious actors. Additionally, compatibility issues with certain hardware drivers and system stability problems required immediate resolution through this out-of-band release.
Overview
KB5077796 is a critical out-of-band cumulative update released on January 17, 2026, for Windows 10 systems running Version 21H2 and 22H2. This update addresses multiple security vulnerabilities and system stability issues that required immediate resolution outside the regular monthly update cycle.
Affected Systems
This update applies to the following Windows 10 versions:
| OS Version | Build Before Update | Build After Update | Status |
|---|---|---|---|
| Windows 10 Version 22H2 | 19045.xxxx | 19045.6811 | Supported |
| Windows 10 Version 21H2 | 19044.xxxx | 19044.6811 | Supported |
All editions of Windows 10 are affected, including Home, Pro, Pro for Workstations, and Enterprise editions.
Security Improvements
This update includes critical security fixes addressing vulnerabilities in core Windows components. The security enhancements focus on:
- Kernel-level security improvements preventing privilege escalation
- Enhanced memory protection mechanisms
- Strengthened access controls for system processes
- Improved authentication and authorization mechanisms
Important: This is a security-critical update that should be installed as soon as possible to protect systems from potential security threats.
System Stability Enhancements
The update resolves several system stability issues that were causing unexpected system behavior:
- Blue screen errors during system startup
- Application crashes and system freezes
- Memory management issues
- Driver compatibility problems
Performance Improvements
Performance optimizations included in this update:
- Improved system resource utilization
- Enhanced hardware compatibility
- Optimized network stack performance
- Reduced system boot times
Enterprise Considerations
For enterprise environments, this update provides:
- Improved domain authentication reliability
- Enhanced Group Policy processing
- Better compatibility with enterprise applications
- Resolved issues with network file sharing
Note: Enterprise administrators should test this update in a controlled environment before widespread deployment.
Installation Process
The installation process for KB5077796 follows standard Windows Update procedures:
- Download phase: Update files are downloaded in the background
- Preparation phase: System prepares for installation
- Installation phase: Update components are installed
- Restart phase: System restart completes the installation
Total installation time typically ranges from 15-30 minutes depending on system specifications and configuration.
Post-Installation Verification
After installing KB5077796, verify successful installation:
Get-HotFix -Id KB5077796Check system build number:
Get-ComputerInfo | Select-Object WindowsVersion, WindowsBuildLabExThe build number should show 19045.6811 for Windows 10 22H2 or 19044.6811 for Windows 10 21H2.
Resolution Methods
Key Fixes & Changes
01
Resolves critical security vulnerabilities in Windows kernel
This update patches multiple security vulnerabilities in the Windows kernel and associated system components. The fixes prevent potential privilege escalation attacks and unauthorized access to system resources. Security enhancements include improved memory protection mechanisms and strengthened access controls for system processes.
02
Fixes system stability issues causing blue screen errors
Addresses critical system stability problems that were causing unexpected blue screen errors (BSOD) during system startup and normal operation. The update includes fixes for memory management issues, driver compatibility problems, and kernel-level exceptions that were leading to system crashes.
03
Improves Windows Update service reliability
Resolves issues with the Windows Update service that were preventing automatic updates from installing correctly. The update includes fixes for update detection mechanisms, download processes, and installation procedures to ensure reliable update delivery.
04
Enhances network connectivity in enterprise environments
Addresses network connectivity issues affecting enterprise deployments, including problems with domain authentication, network discovery, and file sharing services. The update improves compatibility with enterprise network infrastructure and resolves DNS resolution issues.
05
Updates system performance and hardware compatibility
Includes performance improvements for system components and enhanced hardware compatibility. The update addresses issues with specific hardware configurations, improves driver compatibility, and optimizes system resource utilization for better overall performance.
Validation
Installation
Installation
KB5077796 is available through multiple distribution channels:
Windows Update
The update is automatically delivered to eligible Windows 10 systems through Windows Update. Systems will receive the update within 24-48 hours of release. To manually check for updates:
- Open Settings > Update & Security > Windows Update
- Click "Check for updates"
- Install
KB5077796when it appears
Microsoft Update Catalog
Manual download is available from the Microsoft Update Catalog for enterprise deployment scenarios. The update package is approximately 890 MB for x64 systems and 680 MB for x86 systems.
Windows Server Update Services (WSUS)
Enterprise environments using WSUS can deploy this update through their existing update infrastructure. The update is classified as "Critical Updates" in WSUS.
System Requirements
- Available disk space: Minimum 2 GB free space on system drive
- System restart: Required after installation
- Installation time: Approximately 15-30 minutes depending on system configuration
- Prerequisites: No specific prerequisites required
If it still fails
Known Issues
Known Issues
The following known issues have been identified with KB5077796:
Installation Failures
Some systems may experience installation failures with error code 0x80070643 if insufficient disk space is available. Ensure at least 2 GB of free space on the system drive before attempting installation.
Third-party Antivirus Compatibility
Certain third-party antivirus solutions may interfere with the update installation process. Temporarily disable real-time protection during installation if update failures occur.
Network Printer Issues
Some users have reported connectivity issues with network printers after installing this update. Restart the Print Spooler service or reinstall printer drivers if printing problems occur.
Workarounds
- For installation failures: Clear Windows Update cache using
net stop wuauserv, delete contents ofC:\Windows\SoftwareDistribution, then restart Windows Update service - For printer issues: Restart Print Spooler service via Services.msc or run
net stop spooler && net start spoolerin elevated command prompt
Frequently Asked Questions
What does KB5077796 resolve?+
KB5077796 resolves critical security vulnerabilities in the Windows kernel, system stability issues causing blue screen errors, Windows Update service reliability problems, network connectivity issues in enterprise environments, and performance problems with certain hardware configurations.
Which systems require KB5077796?+
KB5077796 is required for Windows 10 Version 21H2 (Build 19044) and Windows 10 Version 22H2 (Build 19045) across all editions including Home, Pro, Pro for Workstations, and Enterprise. The update brings systems to builds 19044.6811 and 19045.6811 respectively.
Is KB5077796 a security update?+
Yes, KB5077796 includes critical security fixes addressing vulnerabilities in core Windows components, particularly the Windows kernel. It includes security enhancements such as improved memory protection mechanisms and strengthened access controls for system processes.
What are the prerequisites for KB5077796?+
KB5077796 has no specific prerequisites but requires a minimum of 2 GB free disk space on the system drive for installation. The update is approximately 890 MB for x64 systems and 680 MB for x86 systems, and requires a system restart to complete installation.
Are there known issues with KB5077796?+
Known issues include potential installation failures with error 0x80070643 due to insufficient disk space, compatibility problems with certain third-party antivirus solutions during installation, and network printer connectivity issues that may require restarting the Print Spooler service.
References (3)
1
January 17, 2026—KB5077796 (OS Builds 19045.6811 and 19044.6811) Out-of-bandOfficial Microsoft support article for KB5077796 out-of-band updatehttps://support.microsoft.com/en-us/topic/january-17-2026-kb5077796-os-builds-19045-6811-and-19044-6811-out-of-band-815b5575-1724-4748-afb5-63b332a0142e
2Windows 10 update historyComplete update history for Windows 10 including cumulative updateshttps://support.microsoft.com/en-us/topic/windows-10-update-history-8127c2c6-6edf-4fdf-8b9f-0f7be1ef3562
3Microsoft Update CatalogDownload standalone packages for Windows updates including KB5077796https://www.catalog.update.microsoft.com/
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