# CVE-2026-6205: Synology DiskStation Manager external control of file name or path in Upload API

Source: https://junglewise.ai/threats/cve-2026-6205-synology-diskstation-manager-external-control-of-file-name-or-path  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-6205 · Severity: high · CVSS 8.1 · Published 2026-09-18

Synology DiskStation Manager (DSM) is a network-attached storage operating system used to manage file storage and backup for businesses and individuals. A flaw in its Upload API allows authenticated users to write arbitrary files to the system and cause service disruptions, potentially compromising data integrity and system availability.

Technologies: [Synology DiskStation Manager (DSM)](https://junglewise.ai/threats/technologies/diskstation-manager-dsm). Vendors: [Synology](https://junglewise.ai/threats/vendors/synology).

## Quick answers

**Is CVE-2026-6205 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-6205 being exploited in the wild.

**How severe is CVE-2026-6205?** High severity, with a CVSS score of 8.1, published 18 September 2026.

**Which products and versions are affected?** Synology DiskStation Manager (DSM) 7.2.1 before 69057-12, 7.2.2 before 72806-9, 7.3.2 before 86009-4, 7.4 before 90075.

**Is there a fix for CVE-2026-6205?** A patch was published on 2026-09-18: Patches released simultaneously with disclosure Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-6205 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-6205?** Check whether you run Synology DiskStation Manager (DSM) 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.

## Technical details

An external control of file name or path vulnerability (CWE-73) exists in the Upload API of Synology DiskStation Manager. The vulnerability allows remote authenticated users to manipulate file paths during upload operations, enabling them to write arbitrary files to unintended locations on the system. Attack requires valid authentication credentials and network access to the DSM web interface. An attacker can achieve arbitrary file write and denial-of-service impacts. Patches are available in DSM 7.2.1-69057-12 or later, 7.2.2-72806-9 or later, 7.3.2-86009-4 or later, and 7.4-90075 or later.

## Affected products

- Synology DiskStation Manager (DSM) 7.2.1 before 69057-12, 7.2.2 before 72806-9, 7.3.2 before 86009-4, 7.4 before 90075

## Timeline

- 2026-09-18: disclosed
- 2026-09-18: patched: Patches released simultaneously with disclosure

## References

- [https://www.synology.com/en-global/security/advisory/Synology_SA_26_13](https://www.synology.com/en-global/security/advisory/Synology_SA_26_13)

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