CVE-2026-53593
What it is
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::$restricted_extensions`) is incomplete: it does not cover the `.pht` extension. The authenticated upload endpoint `POST /uploads/upload` (`SecureController@upload`) stores files with their original extension into the web-accessible directory `storage/app/public/uploads/` (served at `/storage/uploads/`). On the standard Apache + `libapache2-mod-php` deployment, the default handler `<FilesMatch ".+\.ph(ar|p[3457]?|t|tml)$">` 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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.4% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.4% in the next 30 days (EPSS).
- Severity: 8.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.4% · EPSS, next 30 days
- Weakness
- CWE-434 · Unrestricted file upload
- Record status
- Deferred
Attack profile CVSS 3.1 · 8.8
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-53593.md and follow it. Check whether this project is affected by CVE-2026-53593. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-27vp-fpg8-j8wv
- https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-27vp-fpg8-j8wv