Critical 10.0Published Mar 3, 2026

CVE-2026-28289FreeScout 1.8.206 Patch Bypass for CVE-2026-27636 via Zero-Width Space Character Leads to Remote Code Execution

Updated under an hour ago (Oct 27, 2026, 5:10 AM ET)

Does this affect you?

It affects freescout-help-desk freescout and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for freescout-help-desk freescout

Exploited in the last 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.

CVSS: 10.0 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Weakness (CWE): CWE-434
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Mar 5, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

freescout-help-desk freescout freescout_help_desk:freescout (from the name)	before 1.8.207	CNA record
freescout freescout freescout:freescout	before 1.8.207	NVD

References

References

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-5gpc-65p8-ffwp	x-refsource-confirm, exploit, mitigation, vendor-advisory
https://github.com/freescout-help-desk/freescout/commit/f7bc16c56a6b13c06da52ad51fd666546b40818f	x-refsource-misc, patch
https://www.ox.security/blog/freescout-rce-cve-2026-28289/	exploit, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.