# CVE-2026-67193: Xlight FTP Server < 3.9.5 Information Disclosure via USER Command

> Unauthenticated attackers can leak server timing information via a crafted USER command, potentially aiding further attacks.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Jul 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-3c72-cvwm-9gqx

## What is CVE-2026-67193?

CVE-2026-67193 is a medium-severity vulnerability in Xlight FTP Server, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Xlight FTP Server before 3.9.5 contains an information disclosure vulnerability that allows unauthenticated attackers to obtain the server's current GetTickCount() value by sending a USER command with a username ending in the :adm suffix. Attackers can trigger the admin protocol path within the standard FTP listener pre-authentication to leak timing information from the FTP 331 response without requiring a separate port or configuration change.

Weakness: CWE-203 (Observable Discrepancy)

## Which versions are affected by CVE-2026-67193?


## How do I fix CVE-2026-67193?

No fix has been published for CVE-2026-67193 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-67193 being exploited?

There is no known exploitation of CVE-2026-67193 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-67193 and fix it if it is affected.

What it is: CVE-2026-67193 is a medium-severity vulnerability in Xlight FTP Server, published on 29 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-67193 in the wild and no public exploit code.

Affected product: Xlight FTP Server. 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-2026-67193/ (Markdown: https://insights.sbomify.com/CVE-2026-67193/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-67193
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-67193
- OSV: https://osv.dev/vulnerability/CVE-2026-67193

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-67193/
Summaries are generated and may contain mistakes; the official description above is the record.