Microsoft confirmed that Windows 11 KB5066835 breaks localhost (127.0.0.1) HTTP/2 connections, which means locally hosted apps can no longer connect to your network, but that’s not the only problem.

Windows updates usually bring security enhancements, bug fixes and new features. Sometimes, though, these updates can also break parts of the operating system. Unfortunately, some updates for ...

Update 10/17/25: Microsoft fixes the bug using a KIR (Known Issue Rollback) update. More information added to end of story. Microsoft's October Windows 11 updates have broken the "localhost" ...

The problem first surfaced on Microsoft's own support forums and quickly spread to Stack Overflow and Server Fault after the October 2025 cumulative update (KB5066835) landed, which appears to have ...

If you encounter the Localhost refused to connect error message when running any web server on your local Windows 11/10 computer, then this post is intended to help ...

Security researchers say Meta and Yandex used native Android apps to listen on localhost ports, allowing them to link web browsing data to user identities and bypass typical privacy protections.

Java 18's Simple Web Server lets you use a command-line tool or API to host files and more. Here's how it works. One of the handiest new features included in the Java 18 release (March 2022) was the ...

If you are running XAMPP or WAMP or any other web server on your local computer, and you face the “Localhost refused to connect” error message, then there is ...