CVEs / CVE-2026-28289
CVE-2026-28289: freescout-help-desk freescout vulnerability
- high 8.1 CVSS 3.1 (NVD)
- EPSS 35.1% chance of exploitation in the next 30 days, higher than 98% of CVEs (30 Oct 2026)
- Last changed at its sources
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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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| freescout-help-desk freescout | < 1.8.207 | — |
Exploitation
Not in the CISA Known Exploited Vulnerabilities catalog as of 30 Oct 2026.
Severity
| CVSS 3.1 | 8.1 highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-434 |
References
- CVE-2026-28289 on NVD
- CVE-2026-28289 on OSV
- https://github.com/freescout-help-desk/freescout/commit/f7bc16c56a6b13c06da52ad51fd666546b40818f Patch
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-5gpc-65p8-ffwp Exploit, Mitigation, Vendor Advisory
- https://www.ox.security/blog/freescout-rce-cve-2026-28289/ Exploit, Vendor Advisory
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.