January 2026 Patch Tuesday: windows Updates Address Security Vulnerabilities and Known Issues
Microsoft released its January 2026 Patch Tuesday updates, addressing a range of security vulnerabilities and known issues affecting Windows operating systems. These updates include fixes for authentication problems with Azure virtual Desktop and Windows 365,a resolution for a login screen icon visibility issue,and teh removal of vulnerable legacy modem drivers. Additionally, the updates prepare systems for upcoming certificate expirations that could impact boot security.
Authentication Issues with Azure Virtual Desktop and Windows 365
Users connecting to azure Virtual Desktop or Windows 365 Cloud PCs via the Windows App may encounter authentication errors and credential prompt failures after installing KB5074109, KB5073455, or KB5073724. Microsoft is working on an out-of-band fix to resolve this issue. As a workaround, enterprise teams should advise affected users to connect using the Remote Desktop client for Windows (MSRDC) or the Windows App Web Client.
Password Icon Visibility Issue
Some users may find that the password icon is missing from the Windows login screen. This issue has persisted as the August 2025 update. Microsoft has released a Known Issue Rollback (KIR) for Pro and Home editions. Enterprise deployments can restore the icon by implementing an updated Group Policy.
Removal of Legacy Modem drivers
These updates intentionally remove legacy Agere and Motorola soft modem drivers (agrsm64.sys, agrsm.sys, smserl64.sys, smserial.sys) to mitigate the elevation of privilege vulnerability detailed in CVE-2023-31096. The presence of these drivers, even without a connected modem, created a security risk, as reported by Krebs on Security. Hardware relying on these drivers will no longer function after applying the January updates.
Upcoming Certificate Expirations
The 2011 certificates currently used by most Windows devices are scheduled to expire in June and October. Devices that do not receive the updated 2023 certificates may experience boot failures or lose access to future Secure Boot security updates.Computerworld previously highlighted this issue in december.
Resolved Issues
The January release addresses several issues impacting enterprise environments. Microsoft will continue to provide details on resolved issues with future updates.