CVE-2026-86158

Missing Authentication in the local .NET backend of Progress Telerik Fiddler Everywhere

Published Sep 29, 2026 CVSS 3.1 · 7.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Progress Software
Progress Software progress Telerik Fiddler Everywhere
Vendors & Products Progress Software
Progress Software progress Telerik Fiddler Everywhere
Type Values Removed Values Added
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.
Title Missing Authentication in the local .NET backend of Progress Telerik Fiddler Everywhere
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 7.7, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
ProgressSoftware
Published
Updated
Sep 30, 2026, 3:28 PM
Reserved
Sep 5, 2026, 9:09 AM
Status
Awaiting Analysis
Published
Sep 29, 2026, 7:16 AM
Modified
Sep 30, 2026, 4:19 PM