CVE-2026-104657
Missing Integrity Verification in Progress Software Fiddler Download & Setup Skill
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.
Fixes and workarounds
Workaround
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.
Source: CNA: ProgressSoftwareAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Fiddler Download & Setup Skill Progress Software |
≥ 0; < 8.3.0 (affected, semver)
Other versions: unaffected |
CNA: ProgressSoftware |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 7.5 high |
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H | CNA: ProgressSoftware |
| 3.1 / 7.5 high |
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H | NVD: [email protected] |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://www.telerik.com/fiddler/fiddler-everywhere/documentation/knowledge-base/kb-security-missing-download-integrity-verification-cve-2026-104657CNA: ProgressSoftware · vendor-advisory
- https://www.telerik.com/fiddler/fiddler-everywhere/documentation/knowledge-base/kb-security-missing-download-integrity-verification-cve-2026-104657[email protected]
For agents and automation
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