CVE-2026-40539

HIGH CVSS 3.1: 7.1 EPSS 0.08%
Updated Sep 18, 2026
Synology
Parameter Value
CVSS 7.1 (HIGH)
Affected Versions before 7.2.1
Type CWE-295 (Improper Certificate Validation)
Vendor Synology
Public PoC No

An improper certificate validation vulnerability in Email API in Synology DiskStation Manager (DSM) before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2 allows man-in-the-middle attackers to read or write arbitrary files and conduct denial-of-service attacks.

Attack Parameters

Attack Vector
Adjacent
Requires local network access
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v3.1