Microsoft January 2026 Updates: Addressing Authentication Issues,Security Vulnerabilities,and Certificate Expiration
Microsoft’s January 2026 Patch Tuesday updates,released on January 13th,2026,bring a mix of crucial security fixes,resolution of known issues,and readiness for upcoming certificate changes.While these updates are essential for maintaining system security and stability, some users are currently experiencing authentication problems wiht Azure Virtual Desktop and Windows 365 Cloud PCs. This article provides a detailed overview of the key changes, potential issues, workarounds, and what IT professionals and end-users need to know.
Authentication Issues with Azure Virtual Desktop and windows 365
Following the installation of KB5074109, KB5073455, or KB5073724, a important number of users connecting to Azure Virtual Desktop (AVD) or Windows 365 Cloud PCs via the Windows App are encountering authentication errors and repeated credential prompts. This issue disrupts remote access and productivity. Microsoft has acknowledged the problem and is actively working on an out-of-band (OOB) fix to address it.
Why this matters: Azure Virtual Desktop and Windows 365 are critical components of many organizations’ remote work strategies. Authentication failures directly impact employee access to essential applications and data. The rapid response with an OOB fix highlights the severity of the issue.
Workaround: Until the OOB fix is available, Microsoft recommends that affected users connect to AVD or Windows 365 using option methods:
- Remote Desktop Client for Windows (MSRDC): This conventional RDP client provides a reliable alternative connection method.
- Windows App Web Client: Accessing AVD or Windows 365 through a web browser bypasses the problematic Windows App. You can find the Web Client here.
Understanding the Impact on Remote Work
The shift to hybrid and remote work models has made reliable remote access solutions like AVD and Windows 365 indispensable. Authentication issues can quickly escalate into widespread disruptions, impacting business continuity. IT departments should proactively communicate these workarounds to their users and monitor the situation closely for updates from Microsoft.
Password Icon Visibility Issue
A cosmetic, but potentially concerning, issue persists from the August 2025 update: the password reveal icon on the Windows login screen might potentially be missing. While not a security vulnerability in itself, it can cause user confusion and anxiety. Microsoft has released a Known Issue Rollback (KIR) for Pro and Home editions to resolve this.
Resolution for Enterprise Deployments: Organizations utilizing enterprise deployments should implement an updated Group Policy to restore the password icon’s visibility. Details on the specific Group Policy settings can be found in the KB5074109 support article.
Critical Security Fix: Removal of Legacy Modem Drivers
This update intentionally removes legacy Agere and Motorola soft modem drivers (agrsm64.sys, agrsm.sys,smserl64.sys, smserial.sys) to mitigate CVE-2023-31096, a serious elevation of privilege vulnerability. Crucially, the presence of these drivers, even if a modem isn’t connected, made systems vulnerable.
Why this is critically important: CVE-2023-31096 allowed attackers to gain elevated privileges on affected systems, potentially leading to complete system compromise. Removing the vulnerable drivers is a proactive step to harden systems against this threat. As KrebsOnSecurity highlights, this vulnerability was a significant concern.
Compatibility Considerations: Hardware that relies on these legacy drivers will cease to function after applying the January updates. Organizations should identify any such hardware and plan for replacements or alternative solutions.This is a prime example of the trade-offs between security and compatibility in software updates.
Preparing for Certificate Expiration
The 2011 certificates currently used by most Windows devices are nearing their expiration date. The first batch will expire in June 2026, with a second batch following in October 2026. Devices that do not receive the updated 2023 certificates may experience boot failures or lose the ability to receive future Secure Boot security updates.
As Computerworld reported in December, this is a long-anticipated event. Ensuring all devices are updated with the new certificates is critical for maintaining system security and preventing disruptions.
what is Secure Boot and Why Does Certificate Expiration Matter?
Secure Boot is a security standard developed by the Unified Extensible Firmware Interface (UEFI) Forum.It helps prevent malicious software from loading during the boot process. Certificates are used to verify the authenticity of boot components. When the certificates expire, the system can no longer reliably verify these components, potentially allowing malware to take control before the operating system even loads.
Resolved Issues
The January release addresses several issues impacting enterprise environments. While a comprehensive list is available in the official Microsoft documentation, some key resolutions include:
- Improved stability for certain printing scenarios.
- Fixes for issues causing high CPU usage in specific applications.
- Resolution of problems with Windows Update failing to install on certain configurations.
Key Takeaways
- Prioritize AVD/Windows 365 Workarounds: Implement the recommended workarounds for authentication issues immediatly.
- Address Password Icon Visibility: Apply the KIR or Group Policy update to restore the password icon.
- Plan for Modem Driver Removal: Identify and replace any hardware dependent on the removed modem drivers.
- prepare for Certificate Updates: Ensure all devices are updated with the new 2023 certificates to avoid boot failures.
- Stay Informed: Regularly check Microsoft’s security update guide for the latest information and updates.
