CVE-2026-86158

HIGHCVSS 7.7

Description

Missing authentication in the local .NET backend (Fiddler.WebUi) of Progress Software Fiddler Everywhere 8.0.2 allows a local unauthenticated attacker to mint OAuth tokens and read the machine-in-the-middle root certificate through an unauthenticated localhost HTTP and SignalR RPC channel.

Timeline

Published:September 29th, 2026 7:16 AM

Last modified:September 30th, 2026 4:19 PM

CVSS Scoring

CVSS v3: 7.7 (HIGH)

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Weaknesses (CWE)

CWE-306

References & Reports

Advisories, patches, and third-party reports

https://www.telerik.com/fiddler/fiddler-everywhere/documentation/knowledge-base/kb-security-missing-authentication-for-critical-function-cve-2026-86158

Source: NIST NVD · Data may lag official sources by up to one minute