# CVE-2026-24721: Null Pointer Dereference in File Station 5

> A remote attacker with a user account can cause a denial-of-service in QNAP File Station 5 via a null pointer dereference.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`)
- **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:** 15 Oct 2026
- **Updated:** 15 Oct 2026
- **Also known as:** GHSA-mfr5-9c36-8rh4

## What is CVE-2026-24721?

CVE-2026-24721 is a medium-severity vulnerability in Qnap File Station, published on 15 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A NULL pointer dereference vulnerability has been reported to affect File Station 5. If a remote attacker gains a user account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack.

We have already fixed the vulnerability in the following version:
File Station 5 5.5.6.5243 and later

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-24721?

It affects 1 product.


Products: Qnap File Station.

## How do I fix CVE-2026-24721?

No fix has been published for CVE-2026-24721 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-24721 being exploited?

There is no known exploitation of CVE-2026-24721 in the wild and no public exploit code.

## Other vulnerabilities in Qnap File Station

- [CVE-2025-29883](https://insights.sbomify.com/CVE-2025-29883/): File Station 5 (high 8.3)
- [CVE-2025-29884](https://insights.sbomify.com/CVE-2025-29884/): File Station 5 (high 8.3)
- [CVE-2025-29885](https://insights.sbomify.com/CVE-2025-29885/): File Station 5 (high 8.3)
- [CVE-2025-30279](https://insights.sbomify.com/CVE-2025-30279/): File Station 5 (high 8.3)
- [CVE-2025-33031](https://insights.sbomify.com/CVE-2025-33031/): File Station 5 (high 8.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-24721 and fix it if it is affected.

What it is: CVE-2026-24721 is a medium-severity vulnerability in Qnap File Station, published on 15 Oct 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-2026-24721 in the wild and no public exploit code.

Affected product: Qnap File Station. 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-2026-24721/ (Markdown: https://insights.sbomify.com/CVE-2026-24721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-24721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-24721
- OSV: https://osv.dev/vulnerability/CVE-2026-24721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-24721/
Summaries are generated and may contain mistakes; the official description above is the record.