CVE-2020-27648: Synology Diskstation Manager

Critical severity, CVSS 9.0. EPSS: 0.7% chance of exploitation in the next 30 days.

Improper certificate validation vulnerability in OpenVPN client in Synology DiskStation Manager (DSM) before 6.2.3-25426-2 allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.

Affected products

• Synology Diskstation Manager: from 6.2, before 6.2.3-25426-2 (fixed in 6.2.3-25426-2)
• Synology Skynas Firmware: before 6.2.3-25426 (fixed in 6.2.3-25426)

Published 2020-10-29. Last modified 2026-06-17.