Detections
Analytics
CVE-2026-28289
high
Description
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.
References
https://www.infosecurity-magazine.com/news/zeroclick-freescout-bug-remote/
https://www.helpnetsecurity.com/2026/03/05/freescout-vulnerability-cve-2026-28289/
https://www.securityweek.com/critical-freescout-vulnerability-leads-to-full-server-compromise/