CVE-2026-28289: Freescout

High severity, CVSS 8.1. EPSS: 2.7% chance of exploitation in the next 30 days.

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.

Affected products

• Freescout Freescout: before 1.8.207 (fixed in 1.8.207)

Published 2026-03-03. Last modified 2026-06-17.