# CVE-2026-53595

## Summary

- **CVE ID:** CVE-2026-53595
- **Severity:** CRITICAL
- **CVSS Score:** 9.4 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L)
- **CWE:** CWE-178, CWE-287, CWE-640
- **Published:** Jul 20, 2026
- **Last Modified:** Jul 21, 2026

## Description

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.224, the public endpoint `POST /user-setup/{hash}/{invite_sent_at}` (`OpenController@userSetupSave`) selects the target account solely by its `invite_hash` column, then overwrites that account's email and password and logs in as it. No authentication, cookie, or prior session is required. After a user activates, FreeScout sets `invite_hash` to the empty string. On MySQL and MariaDB, `VARCHAR` equality ignores trailing spaces, so a single URL-encoded space (`%20`) matches the stored empty string and selects the lowest-id activated user. The expiry guard decrypts `invite_sent_at` with the target's password hash, but `Helper::decrypt` returns its raw input unchanged when decryption fails. A plaintext numeric value such as `9999999999` therefore passes the time-to-live check without any secret. The result is that an anonymous attacker sets the email and password of the lowest-id activated FreeScout account (a support agent, or an administrator if one was added by invitation) and authenticates as that account. Version 1.8.224 contains a fix.

## Affected Products

- freescout-help-desk — freescout (< 1.8.224)

## References

- [CNA](https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-jqj5-r72v-v29g)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.62%
- **EPSS Percentile:** 47.5

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._