# CVE-2026-40535: Synology DiskStation Manager path traversal in Desktop API

Source: https://junglewise.ai/threats/cve-2026-40535-synology-diskstation-manager-path-traversal-in-desktop-api  
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-2026-40535 · Severity: medium · CVSS 6.5 · Published 2026-09-18

Synology DiskStation Manager (DSM) is the operating system that powers Synology NAS storage devices, widely used by businesses and individuals for data backup and file sharing. A path traversal vulnerability in the Desktop API allows unauthenticated attackers to write limited files and cause service disruptions, potentially compromising data integrity and system availability on affected NAS devices.

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

## Quick answers

**Is CVE-2026-40535 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-40535 being exploited in the wild.

**How severe is CVE-2026-40535?** Medium severity, with a CVSS score of 6.5, published 18 September 2026.

**Which products and versions are affected?** Synology DiskStation Manager before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2.

**Is there a fix for CVE-2026-40535?** A patch was published on 2026-04-15: Patches released: DSM 7.2.1-69057-10, 7.2.2-72806-7, 7.3.2-86009-2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-40535 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-40535?** 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.

## Technical details

CVE-2026-40535 is a path traversal (CWE-22) vulnerability in the Desktop API component of Synology DSM. The vulnerability allows remote attackers without authentication (PR:N) to write limited files and conduct limited denial-of-service attacks via specially crafted requests over the network (AV:N, AC:L). The attack requires no user interaction and affects the integrity and availability of the system. Patches are available in DSM 7.2.1-69057-10, 7.2.2-72806-7, and 7.3.2-86009-2 or later.

## Affected products

- Synology DiskStation Manager before 7.2.1-69057-10, 7.2.2-72806-7 and 7.3.2-86009-2

## Timeline

- 2026-04-15: disclosed
- 2026-04-15: patched: Patches released: DSM 7.2.1-69057-10, 7.2.2-72806-7, 7.3.2-86009-2
- 2026-09-18: advisory

## References

- [https://www.synology.com/en-global/security/advisory/Synology_SA_26_06](https://www.synology.com/en-global/security/advisory/Synology_SA_26_06)

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