A recent Microsoft update for Windows 11 has caused a critical networking failure in the Windows Subsystem for Linux, disrupting users' access to virtual private servers. The issue affects developers and organizations relying on WSL mirror networking. Microsoft has acknowledged the problem but provided few details on a fix.
Microsoft released KB5067036, a non-security preview update for Windows 11 versions 25H2 and 24H2, targeting OS builds 26200.7019 and 26100.7019. Designed to enhance functionality, performance, and reliability, the update instead introduced a significant networking problem within the Windows Subsystem for Linux (WSL).
The core issue involves the failure of mirror networking in WSL, a feature vital for maintaining connectivity between Windows host systems and Linux guest environments. This breakdown severely hampers users' ability to connect to virtual private servers (VPS), potentially interrupting development and testing workflows in production settings. Developers and organizations dependent on seamless network access have voiced concerns over the disruption.
In its official release notes, Microsoft listed this under the 'Known Issues' section but offered limited information on the underlying cause or an expected resolution timeline. The lack of detailed guidance has prompted caution among the Windows development community, especially for those managing WSL instances in active use.
The update also brings two broader issues for Windows 11 users: Task Manager may persist in the background after closure, consuming unnecessary resources, and the password icon could appear missing or invisible on the lock-screen sign-in interface.
Distribution occurs in phases—a gradual rollout to select devices over time, followed by a routine deployment to all eligible systems. Additionally, KB5067036 incorporates a servicing stack update (KB5067035) and refreshes AI components for Copilot+ features, such as Image Search, Content Extraction, Semantic Analysis, and the Settings Model, all to version 1.2510.1152.0.
Affected users should monitor the Windows release health dashboard and update history for versions 24H2 and 25H2 to stay informed on patches. Microsoft has yet to specify when a fix for the WSL networking problem will arrive, advising deferral of installation where possible.