CVE-2026-40539: Improper Certificate Validation in Synology DiskStation Manager (DSM)
CVE-2026-40539 is a high-severity vulnerability in Synology DiskStation Manager (DSM) affecting the Email API. It involves improper certificate validation that could allow man-in-the-middle attackers to read or write arbitrary files and cause denial-of-service conditions. The issue affects specific versions before the patched releases 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2.
AI Analysis
Technical Summary
This vulnerability in Synology DSM's Email API is due to improper certificate validation, enabling attackers positioned in a man-in-the-middle role to intercept and manipulate communications. Exploitation could lead to unauthorized reading or writing of files and denial-of-service attacks. The flaw affects versions prior to 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2, which have addressed the issue.
Potential Impact
Successful exploitation allows an attacker to read or write arbitrary files on the affected system and perform denial-of-service attacks, potentially disrupting service availability and compromising data confidentiality and integrity.
Mitigation Recommendations
A fix is available in Synology DiskStation Manager versions 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2. Users should update to these or later versions to remediate the vulnerability.
CVE-2026-40539: Improper Certificate Validation in Synology DiskStation Manager (DSM)
Description
CVE-2026-40539 is a high-severity vulnerability in Synology DiskStation Manager (DSM) affecting the Email API. It involves improper certificate validation that could allow man-in-the-middle attackers to read or write arbitrary files and cause denial-of-service conditions. The issue affects specific versions before the patched releases 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2.
CVSS v3.1
Score 7.1high
Affected software
Synology
DiskStation Manager (DSM)
pkg:rpm/synology/diskstation-managerRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in Synology DSM's Email API is due to improper certificate validation, enabling attackers positioned in a man-in-the-middle role to intercept and manipulate communications. Exploitation could lead to unauthorized reading or writing of files and denial-of-service attacks. The flaw affects versions prior to 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2, which have addressed the issue.
Potential Impact
Successful exploitation allows an attacker to read or write arbitrary files on the affected system and perform denial-of-service attacks, potentially disrupting service availability and compromising data confidentiality and integrity.
Mitigation Recommendations
A fix is available in Synology DiskStation Manager versions 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2. Users should update to these or later versions to remediate the vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- synology
- Date Reserved
- 2026-04-14T01:01:14.607Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6aad16b655bf5e2cf5e64356
Added to database: 09/18/2026, 10:47:18 UTC
Last enriched: 09/18/2026, 11:01:29 UTC
Last updated: 09/18/2026, 11:21:46 UTC
Views: 6
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