CVE-2025-41256 Cyberduck and Mountain Duck - Weak Hash Algorithm for Certificate Fingerprint
Attackers can bypass TLS certificate pinning in Cyberduck and Mountain Duck due to the use of the weak SHA-1 hash algorithm for certificate fingerprints.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-41256?
CVE-2025-41256 is a high-severity vulnerability in iterate GmbH Cyberduck, published on 25 Jun 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Cyberduck and Mountain Duck improper handle TLS certificate pinning for untrusted certificates (e.g., self-signed), since the certificate fingerprint is stored as SHA-1, although SHA-1 is considered weak.
This issue affects Cyberduck: through 9.1.6; Mountain Duck: through 4.17.5.
Weakness: CWE-328
Which versions are affected by CVE-2025-41256?
How do I fix CVE-2025-41256?
No fix has been published for CVE-2025-41256 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-41256 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-41256 exists.
Sources
Also known as GHSA-688c-vjrc-84rv, GHSA-qq37-7frg-jxx4.