CVE-2026-28289
In your normal cycle
Critical by CVSS (10), but no sign of active exploitation.
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.
Scoring
| CVSS | 10.0 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| EPSS | 2.66% — more likely to be exploited than 85% of all CVEs |
| Weakness | CWE-434 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2026-03-03 |
| Last modified | 2026-06-17 |
Affected (1)
| Vendor | Product |
|---|---|
| freescout | freescout |
References
→ the Explorer · watch your stack · NVD