CVE-2026-28289HIGH 8.1EPSS p98.0%
CVE-2026-28289CVE-2026-28289
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 3.1 | 8.1 (HIGH) |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 31.14% probability of exploitation · percentile 98.0% · 2026-06-18T12:00:27Z |
| Published | 2026-03-03 |
| Last modified | 2026-03-11 |
Underlying weaknesses· 1
References
1
| Type | Target | Confidence | Tier |
|---|---|---|---|
| Weakness | Unrestricted Upload of File with Dangerous Typecwe-434 | 0% | live |
Related by meaning· 6
Nearest entities by semantic similarity across the cs-graph corpus.