# CVE-2025-65403: 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.

Source: https://junglewise.ai/threats/cve-2025-65403-a-buffer-overflow-in-the-g-cfg-maxusers-component-of-lightftp-v2  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2025-12-01  
License: CC BY 4.0 with a link back

CVE-2025-65403 · Severity: medium · CVSS 6.5 · Published 2025-12-01

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.

Technologies: [Hfiref0x LightFTP](https://junglewise.ai/threats/technologies/lightftp). Vendors: [Hfiref0x](https://junglewise.ai/threats/vendors/hfiref0x).

## Quick answers

**Is CVE-2025-65403 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-65403 being exploited in the wild.

**How severe is CVE-2025-65403?** Medium severity, with a CVSS score of 6.5, published 1 December 2025.

**Which products and versions are affected?** Hfiref0x LightFTP. The advisory does not name versions.

**Is there a fix for CVE-2025-65403?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2025-65403?** Check whether you run Hfiref0x LightFTP. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Hfiref0x LightFTP

## Related threats

- [LightFTP data race condition in ftpserv.c](https://junglewise.ai/threats/cve-2026-70637-lightftp-data-race-condition-in-ftpserv-c)
- [hfiref0x LightFTP race condition in worker thread cleanup](https://junglewise.ai/threats/cve-2026-67607-hfiref0x-lightftp-race-condition-in-worker-thread-cleanup)