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Fencer Intel
high 8.0

CVE-2025-41255 json

Cyberduck and Mountain Duck - Improper Certificate Store Handling

published last yr. modified 4mo ago also EUVD-2025-19096

cvss
8.0
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 8%
public exploits
0
none known

Summary

Cyberduck and Mountain Duck improperly handle TLS certificate pinning for untrusted certificates (e.g., self-signed), unnecessarily installing it to the Windows Certificate Store of the current user without any restrictions.

This issue affects Cyberduck through 9.1.6 and Mountain Duck through 4.17.5.

Is CVE-2025-41255 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last yr.

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/sbaresearch/advisories/tree/public/2025/SBA-ADV-20250325-01_Cyberduck_Mountain_Duck_Certificate_Handling referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/iterate-ch/cyberduck/security/advisories/GHSA-vjjc-grpp-m655 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.0 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N

Affected products

  • iterate GmbH Cyberduck
  • iterate GmbH Mountain Duck

Classification

Weakness
  • CWE-266 Incorrect Privilege Assignment

References

Sources

Fencer Intel 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.