CVE-2026-28289

CRITICAL

10.0

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.

CVE Details

CVSS v3.1 Score10.0

SeverityCRITICAL

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

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published3/3/2026

Last Modified3/11/2026

Sourcenvd

Honeypot Sightings0

Affected Products

freescout:freescout

Weaknesses (CWE)

CWE-434

References

https://github.com/freescout-help-desk/freescout/commit/f7bc16c56a6b13c06da52ad51fd666546b40818f(security-advisories@github.com)

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-5gpc-65p8-ffwp(security-advisories@github.com)

https://www.ox.security/blog/freescout-rce-cve-2026-28289/(af854a3a-2127-422b-91ae-364da2661108)

IOC Correlations

No correlations recorded

This product uses data from the NVD API but is not endorsed or certified by the NVD.