Missing Integrity Verification in Progress Software Fiddler Download & Setup Skill

published 2026-11-06 2 d ago modified 2026-11-09 1 h ago also EUVD-2026-118358

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits: 0; none known

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.

Patch / fix

fixed in 1

Progress Software Fiddler Download & Setup Skill 8.3.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 2 d ago (2026-11-06)

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected products

Progress Software Fiddler Download & Setup Skill

Classification

Weakness

CWE-494 Download of Code Without Integrity Check
CWE-377 DEPRECATED: Insecure Temporary File

References

telerik.com /fiddler/fiddler-everywhere/documentation/knowledge-base/kb-security-missing-download-integrity-verification-c
vendor-advisory

Sources

CVE List CVE-2026-104657
NVD CVE-2026-104657

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary