CVE-2026-40539

HIGH

7.1

CVSS Score

Published: September 18, 2026 at 08:29 AM UTC

Updated: September 18, 2026 at 07:19 PM UTC

1 product affected across 1 vendorDiskStation Manager

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Severity

HIGH7.1

Exploit prediction

EPSS 0.1%

SSVC

No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

DiskStation Manager · Synology

60%

7.2.1 ≤ v < 7.2.1-69057-107.2.2 ≤ v < 7.2.2-72806-77.3 ≤ v < 7.3.2-86009-27.2.1 7.2.2 7.3

Affected range stops below 7.2.1-69057-10, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.2.2-72806-7, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.3.2-86009-2, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 7.2.1 (unknown)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

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

References (1)

Vendor Advisory

Source: cverecord

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

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHsynology

Attack Vector: ADJACENT_NETWORK
Complexity: HIGH
Privileges: NONE
User Interaction: REQUIRED
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusAWAITING ANALYSIS

CWE

CWE-295

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