# CVE-2026-6205: Path traversal in DiskStation Manager (DSM)

> Remote authenticated users can write arbitrary files and cause denial of service via path traversal in the Upload API.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-357v-8fxm-wwhq

## What is CVE-2026-6205?

CVE-2026-6205 is a high-severity path traversal vulnerability in Synology DiskStation Manager (DSM), published on 18 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An external control of file name or path vulnerability in Upload API in Synology DiskStation Manager (DSM) before 7.2.1-69057-12, 7.2.2-72806-9, 7.3.2-86009-4 and 7.4-90075 allows remote authenticated users to write arbitrary files and conduct denial-of-service attacks.

Weakness: CWE-73 (External Control of File Name or Path)

## Which versions are affected by CVE-2026-6205?


## How do I fix CVE-2026-6205?

No fix has been published for CVE-2026-6205 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-6205 being exploited?

There is no known exploitation of CVE-2026-6205 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-6205 and fix it if it is affected.

What it is: CVE-2026-6205 is a high-severity path traversal vulnerability in Synology DiskStation Manager (DSM), published on 18 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-6205 in the wild and no public exploit code.

Affected product: Synology DiskStation Manager (DSM). No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-6205/ (Markdown: https://insights.sbomify.com/CVE-2026-6205/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-6205
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-6205
- OSV: https://osv.dev/vulnerability/CVE-2026-6205

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-6205/
Summaries are generated and may contain mistakes; the official description above is the record.