CVE-2026-40539 - Vulnerability Details - OpenCVE

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.

No CVSS v4.0

Attack Vector Adjacent Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact total

Vendors	Products
Synology	Diskstation Manager

No data.

No data.

References

Link	Providers
https://www.synology.com/en-global/security/advisory/Synology_SA_26_06

History

Sat, 19 Sep 2026 22:30:00 +0000

Type	Values Removed	Values Added
First Time appeared		Synology Synology diskstation Manager
Vendors & Products		Synology Synology diskstation Manager

Sat, 19 Sep 2026 20:45:00 +0000

Type	Values Removed	Values Added
Title	Improper Certificate Validation in Synology DSM Email API Enables Remote File Access and DoS

Sat, 19 Sep 2026 01:15:00 +0000

Type	Values Removed	Values Added
Title		Improper Certificate Validation in Synology DSM Email API Enables Remote File Access and DoS

Fri, 18 Sep 2026 11:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}`

Fri, 18 Sep 2026 08:45:00 +0000

Type	Values Removed	Values Added
Description		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.
Weaknesses		CWE-295
References		https://www.synology.com/en-global/security/advisory/Synology_SA_26_06
Metrics		cvssV3_1 `{'score': 7.1, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H'}`

MITRE

Status: PUBLISHED

Assigner: synology

Published: 2026-09-18T08:29:33.365Z

Updated: 2026-09-18T10:40:16.842Z

Reserved: 2026-04-14T01:01:14.607Z

Link: CVE-2026-40539

Vulnrichment

Updated: 2026-09-18T10:39:56.419Z

NVD

Status : Awaiting Analysis

Published: 2026-09-18T09:16:41.423

Modified: 2026-09-18T19:07:38.320

Link: CVE-2026-40539

Redhat

No data.

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