CVE-2026-86158

Name of the Vulnerable Software and Affected Versions Progress Software Fiddler Everywhere version 8.0.2

Description Missing authentication in the local .NET backend (Fiddler.WebUi) allows a local unauthenticated attacker to mint OAuth tokens and read the machine-in-the-middle root certificate. This is achieved through an unauthenticated localhost HTTP and SignalR RPC channel. SignalR is a library that simplifies adding real-time web functionality to applications.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.