# CVE-2026-47790: Privilege Escalation via QuFTP Log-based XSS

> Remote attackers with user accounts can inject malicious code via XSS in QuFTP Service, leading to privilege escalation.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:L/VI:N/VA:N/SC:H/SI:H/SA:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 15 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** GHSA-g9jq-pqxh-j9mj

## What is CVE-2026-47790?

CVE-2026-47790 is a medium-severity cross-site scripting vulnerability in QNAP Systems Inc. QuFTP Service, published on 15 Oct 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A cross-site scripting (XSS) vulnerability has been reported to affect QuFTP Service. If a remote attacker gains a user account, they can then exploit the vulnerability to inject malicious code.

We have already fixed the vulnerability in the following version:
QuFTP Service 1.4.6 and later
QuFTP Service 1.5.5 and later
QuFTP Service 1.6.5 and later

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-47790?


## How do I fix CVE-2026-47790?

No fix has been published for CVE-2026-47790 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-47790 being exploited?

There is no known exploitation of CVE-2026-47790 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-47790 and fix it if it is affected.

What it is: CVE-2026-47790 is a medium-severity cross-site scripting vulnerability in QNAP Systems Inc. QuFTP Service, published on 15 Oct 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-47790 in the wild and no public exploit code.

Affected product: QNAP Systems Inc. QuFTP Service. 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-2026-47790/ (Markdown: https://insights.sbomify.com/CVE-2026-47790/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-47790
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-47790
- OSV: https://osv.dev/vulnerability/CVE-2026-47790

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-47790/
Summaries are generated and may contain mistakes; the official description above is the record.