CVE-2026-19048: Synology DiskStation Manager improper link resolution in thumbnail service

CVE-2026-19048 · Severity: high · CVSS 8.1 · Published 2026-11-12

Synology DiskStation Manager is network-attached storage software that manages file access and sharing. A flaw in the thumbnail generation service allows authenticated users to write arbitrary files and cause service disruptions, potentially leading to data corruption or system compromise.

Technologies: Synology DiskStation Manager. Vendors: Synology.

Quick answers

Is CVE-2026-19048 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-19048 being exploited in the wild.
How severe is CVE-2026-19048?
High severity, with a CVSS score of 8.1, published 12 November 2026.
Which products and versions are affected?
Synology DiskStation Manager before 7.3.2-86009-5 and 7.4.x before 7.4.1-90080-1.
Is there a fix for CVE-2026-19048?
Yes: fixed in DSM 7.3.2-86009-5, 7.4.1-90080-1 or above. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-19048 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-19048?
Check whether you run Synology DiskStation Manager at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Fixed in: DSM 7.3.2-86009-5, 7.4.1-90080-1 or above

Technical details

An improper link resolution vulnerability (CWE-59) in the thumbnail service fails to properly validate symbolic links before file access, allowing authenticated attackers to write files outside intended directories. The vulnerability requires authentication and network access; no user interaction is needed. An attacker can write arbitrary files or trigger denial-of-service conditions on the NAS device.

Affected products

  • Synology DiskStation Manager before 7.3.2-86009-5 and 7.4.x before 7.4.1-90080-1

Timeline

  • 2026-11-10: disclosed
  • 2026-11-12: advisory

References

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