{"id":"CVE-2026-53593","aliases":["EUVD-2026-46083","GHSA-27vp-fpg8-j8wv"],"status":"published","title":"FreeScout Vulnerable to Authenticated Remote Code Execution via incomplete upload extension denylist (.pht) — bypass of CVE-2025-48471","description":"FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the denylist that neutralizes dangerous file uploads (`Helper::$restricted_extensions`) is incomplete: it does not cover the `.pht` extension. The authenticated upload endpoint `POST /uploads/upload` (`SecureController@upload`) stores files with their original extension into the web-accessible directory `storage/app/public/uploads/` (served at `/storage/uploads/`). On the standard Apache + `libapache2-mod-php` deployment, the default handler `\u003cFilesMatch \".+\\.ph(ar|p[3457]?|t|tml)$\"\u003e` executes `.pht`, so **any authenticated agent can upload a `.pht` web shell and run arbitrary commands as the web-server user** (`www-data`). This is a direct bypass of the fix for CVE-2025-48471, which added `phtml`/`phar` but not `pht` (nor `phtm`, `phps`). Version 1.8.224 contains an updated fix.","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00351,"percentile":0.2903,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-434"],"published":"2026-07-20T19:52:33Z","modified":"2026-10-28T02:31:02Z","products":[{"vendor":"freescout-help-desk","product":"freescout"}],"references":[{"url":"https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-27vp-fpg8-j8wv","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53593.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53593","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-53593","title":"FreeScout Vulnerable to Authenticated Remote Code Execution via incomplete upload extension denylist (.pht) — bypass of CVE-2025-48471","description":"FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the denylist that neutralizes dangerous file uploads (`Helper::$restricted_extensions`) is incomplete: it does not cover the `.pht` extension. The authenticated upload endpoint `POST /uploads/upload` (`SecureController@upload`) stores files with their original extension into the web-accessible directory `storage/app/public/uploads/` (served at `/storage/uploads/`). On the standard Apache + `libapache2-mod-php` deployment, the default handler `\u003cFilesMatch \".+\\.ph(ar|p[3457]?|t|tml)$\"\u003e` executes `.pht`, so **any authenticated agent can upload a `.pht` web shell and run arbitrary commands as the web-server user** (`www-data`). This is a direct bypass of the fix for CVE-2025-48471, which added `phtml`/`phar` but not `pht` (nor `phtm`, `phps`). Version 1.8.224 contains an updated fix.","status":"published","published":"2026-07-20T19:52:33.06Z","modified":"2026-07-21T14:56:31.717Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T14:19:59.761005Z"}],"euvd":[{"id":"EUVD-2026-46083","description":"FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the denylist that neutralizes dangerous file uploads (`Helper::$restricted_extensions`) is incomplete: it does not cover the `.pht` extension. The authenticated upload endpoint `POST /uploads/upload` (`SecureController@upload`) stores files with their original extension into the web-accessible directory `storage/app/public/uploads/` (served at `/storage/uploads/`). On the standard Apache + `libapache2-mod-php` deployment, the default handler `\u003cFilesMatch \".+\\.ph(ar|p[3457]?|t|tml)$\"\u003e` executes `.pht`, so **any authenticated agent can upload a `.pht` web shell and run arbitrary commands as the web-server user** (`www-data`). This is a direct bypass of the fix for CVE-2025-48471, which added `phtml`/`phar` but not `pht` (nor `phtm`, `phps`). Version 1.8.224 contains an updated fix.","status":"published","published":"2026-07-20T19:52:33Z","modified":"2026-07-21T14:56:31Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T18:19:47.436242Z"}],"nvd":[{"id":"CVE-2026-53593","description":"FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the denylist that neutralizes dangerous file uploads (`Helper::$restricted_extensions`) is incomplete: it does not cover the `.pht` extension. The authenticated upload endpoint `POST /uploads/upload` (`SecureController@upload`) stores files with their original extension into the web-accessible directory `storage/app/public/uploads/` (served at `/storage/uploads/`). On the standard Apache + `libapache2-mod-php` deployment, the default handler `\u003cFilesMatch \".+\\.ph(ar|p[3457]?|t|tml)$\"\u003e` executes `.pht`, so **any authenticated agent can upload a `.pht` web shell and run arbitrary commands as the web-server user** (`www-data`). This is a direct bypass of the fix for CVE-2025-48471, which added `phtml`/`phar` but not `pht` (nor `phtm`, `phps`). Version 1.8.224 contains an updated fix.","status":"published","published":"2026-07-20T20:16:44.883Z","modified":"2026-10-24T20:10:00.137Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T14:12:31.024898Z"}],"osv":[{"id":"CVE-2026-53593","title":"FreeScout Vulnerable to Authenticated Remote Code Execution via incomplete upload extension denylist (.pht) — bypass of CVE-2025-48471","description":"FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the denylist that neutralizes dangerous file uploads (`Helper::$restricted_extensions`) is incomplete: it does not cover the `.pht` extension. The authenticated upload endpoint `POST /uploads/upload` (`SecureController@upload`) stores files with their original extension into the web-accessible directory `storage/app/public/uploads/` (served at `/storage/uploads/`). On the standard Apache + `libapache2-mod-php` deployment, the default handler `\u003cFilesMatch \".+\\.ph(ar|p[3457]?|t|tml)$\"\u003e` executes `.pht`, so **any authenticated agent can upload a `.pht` web shell and run arbitrary commands as the web-server user** (`www-data`). This is a direct bypass of the fix for CVE-2025-48471, which added `phtml`/`phar` but not `pht` (nor `phtm`, `phps`). Version 1.8.224 contains an updated fix.","status":"published","published":"2026-07-20T19:52:33.06Z","modified":"2026-10-28T02:31:02.515092964Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-434"],"updated_at":"2026-11-02T15:45:08.132336Z"}]}}