What’s Vulnerable › Vulnerabilities

CVE-2025-41256: Cyberduck and Mountain Duck - Weak Hash Algorithm for Certificate Fingerprint

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-06-25 · updated 2026-06-17
• Weakness: CWE-328

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.

Affected products

• iterate GmbH Cyberduck: through 9.1.6
• iterate GmbH Mountain Duck: through 4.17.5

References

• https://github.com/iterate-ch/cyberduck/security/advisories/GHSA-688c-vjrc-84rv
• https://github.com/sbaresearch/advisories/tree/public/2025/SBA-ADV-20250325-02_Cyberduck_Mountain_Duck_Weak_Hash
• https://github.com/iterate-ch/cyberduck/security/advisories/GHSA-688c-vjrc-84rv
• https://github.com/sbaresearch/advisories/tree/public/2025/SBA-ADV-20250325-02_Cyberduck_Mountain_Duck_Weak_Hash

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