---
id: CVE-2026-104657
title: >-
  Missing Integrity Verification in Progress Software Fiddler Download & Setup
  Skill
summary: >-
  Missing integrity verification in the Progress Software Fiddler Download and
  Setup Skill on Linux, macOS, and Windows which allows an attacker to
  compromise or influence a release component and execute attacker-controlled
  code when a use…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
cwe:
  - CWE-494
  - CWE-377
vendor: Progress Software
product: Fiddler Download & Setup Skill
affected:
  - fiddler_download_setup_skill < 8.3.0
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-11-06T17:14:11.732315Z'
published: '2026-11-06'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T17:47:49.791Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-104657'
references:
  - url: >-
      https://www.telerik.com/fiddler/fiddler-everywhere/documentation/knowledge-base/kb-security-missing-download-integrity-verification-cve-2026-104657
tags:
  - cve.org
ingestedAt: '2026-11-06T16:57:43.263Z'
epss: 0.00169
epssPercentile: 0.06341
---

## Overview

Missing integrity verification in the Progress Software Fiddler Download and Setup Skill on Linux, macOS, and Windows which allows an attacker to compromise or influence a release component and execute attacker-controlled code when a user runs the skill. On macOS, the skill stages the package at a predictable path and installs it with administrator privileges, which may allow code execution with root privileges after user approval. A local process may also replace the staged macOS package while the skill waits for approval.

## Affected

- `fiddler_download_setup_skill < 8.3.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

### Workarounds

Do not run the affected skill version. Install Fiddler manually from the official distribution source, verify the downloaded artifact's publisher signature and available checksum, and on macOS use a per-user DMG installation without administrator privileges.