# CVE-2025-65403: Memory corruption in n/a

> Attackers can cause a Denial of Service in LightFTP via a buffer overflow in the MaxUsers component.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Dec 2025
- **Updated:** 1 Dec 2025
- **Also known as:** GHSA-2h9h-pcw6-4f34

## What is CVE-2025-65403?

CVE-2025-65403 is a medium-severity memory corruption vulnerability in n/a, published on 1 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A buffer overflow in the g_cfg.MaxUsers component of LightFTP v2.0 allows attackers to cause a Denial of Service (DoS) via a crafted input.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2025-65403?

It affects 1 product.


Products: Hfiref0x Lightftp.

## How do I fix CVE-2025-65403?

No fix has been published for CVE-2025-65403 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-65403 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-65403 exists.

## Other vulnerabilities in n/a

- [CVE-2017-1000218](https://insights.sbomify.com/CVE-2017-1000218/): Memory corruption in n/a (critical 9.8)
- [CVE-2023-24042](https://insights.sbomify.com/CVE-2023-24042/): Race condition in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-65403 and fix it if it is affected.

What it is: CVE-2025-65403 is a medium-severity memory corruption vulnerability in n/a, published on 1 Dec 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-65403 exists.

Affected product: n/a. 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-2025-65403/ (Markdown: https://insights.sbomify.com/CVE-2025-65403/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-65403
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-65403
- OSV: https://osv.dev/vulnerability/CVE-2025-65403

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-65403/
Summaries are generated and may contain mistakes; the official description above is the record.