Improper Certificate Validation in DiskStation Manager (DSM) - CVE-2026-40539
Published: April 16, 2026
Vulnerability identifier: #VU126272
CSH Severity: Medium
CVSS v4: 7.3 [CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-40539
CWE-ID: CWE-295
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to read or write arbitrary files and cause a denial of service.
The vulnerability exists due to improper certificate validation in DSM when establishing adjacent-network connections. A remote attacker can perform a man-in-the-middle attack to read or write arbitrary files and cause a denial of service.
User interaction is required.
Affected software
DiskStation Manager (DSM)
How to mitigate CVE-2026-40539
Install security update from vendor's website.
DiskStation Manager (DSM) - addressed in versions 7.2.1-69057-10, 7.2.2-72806-7, 7.3.2-86009-2