---
cve: "CVE-2026-28289"
severity: "CRITICAL"
cvss: 10.0
epss: "31.1%"
vendor: "freescout-help-desk"
kev: false
exploited: false
published: "2026-03-03 23:15:56"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-09-08T22:06:00+02:00"
---

# CVE-2026-28289

> 10.0 CRITICAL · 🧪 PoC

## Beschreibung

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. A patch bypass vulnerability for CVE-2026-27636 in FreeScout 1.8.206 and earlier allows any authenticated user with file upload permissions to achieve Remote Code Execution (RCE) on the server by uploading a malicious .htaccess file using a zero-width space character prefix to bypass the security check. The vulnerability exists in the sanitizeUploadedFileName() function in app/Http/Helper.php. The function contains a Time-of-Check to Time-of-Use (TOCTOU) flaw where the dot-prefix check occurs before sanitization removes invisible characters. This vulnerability is fixed in 1.8.207.

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- 152e60f672178c7de75d948ab42db5e37481e623 (Commit)
- f7bc16c56a6b13c06da52ad51fd666546b40818f (Commit)

## Referenzen

- <https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-5gpc-65p8-ffwp>
- <https://github.com/freescout-help-desk/freescout/commit/f7bc16c56a6b13c06da52ad51fd666546b40818f>
- <https://www.ox.security/blog/freescout-rce-cve-2026-28289/>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-28289) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_