← Vulnerability feed

Vulnerability record · CVE-2025-54366 · published 26 July 2025

CVE-2025-54366: Freescout deserialization of untrusted data vulnerability

Freescout · Freescout

FreeScout is a lightweight free open source help desk and shared inbox built with PHP (Laravel framework). In versions 1.8.185 and below, there is a critical deserialization vulnerability in the /conversation/ajax endpoint that allows authenticated users with knowledge of the APP_KEY to achieve remote code execution. The vulnerability occurs when the application processes the attachments_all and attachments POST parameters through the insecure Helper::decrypt() function, which performs unsafe deserialization of user-controlled data without proper validation. This flaw enables attackers to create arbitrary objects and manipulate their properties, leading to complete compromise of the web application. This is fixed in version 1.8.186.

8.6 CVSS 4.0 High EPSS 0.98% · top 39.3% CWE-502 · Deserialization of untrusted data
8.6CVSS 4.0 base score
0.98%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References, 1 tagged exploit
17 Jun 2026Last modified by NVD

Description

FreeScout is a lightweight free open source help desk and shared inbox built with PHP (Laravel framework). In versions 1.8.185 and below, there is a critical deserialization vulnerability in the /conversation/ajax endpoint that allows authenticated users with knowledge of the APP_KEY to achieve remote code execution. The vulnerability occurs when the application processes the attachments_all and attachments POST parameters through the insecure Helper::decrypt() function, which performs unsafe deserialization of user-controlled data without proper validation. This flaw enables attackers to create arbitrary objects and manipulate their properties, leading to complete compromise of the web application. This is fixed in version 1.8.186.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/freescout-help-desk/freescout/commit/9669c57f1ddbee896752d9e16270abfd97b20eb9 Patch
https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-vcc2-6r66-gvvj ExploitVendor Advisory

Track CVE-2025-54366 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2026-27637Freescout vulnerabilityFreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.206, FreeScout's `TokenAuth` middleware uses …EPSS 0.84%9.3CVE-2026-32754Freescout cross-site scripting vulnerabilityFreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Versions 1.8.208 and below are vulnerable to Stored Cross-Site Scr…EPSS 0.62%9.0CVE-2024-29185Freescout os command injection vulnerabilityFreeScout is a self-hosted help desk and shared mailbox. Versions prior to 1.8.128 are vulnerable to OS Command Injection in the /public/tools.php so…EPSS 1.7%8.9CVE-2026-40498Freescout information exposure vulnerabilityFreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, an unauthenticated attacker can access diagnostic and system …EPSS 0.73%8.8CVE-2026-40496Freescout vulnerabilityFreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.213, attachment download tokens are generated using a weak and pre…EPSS 0.55%8.8CVE-2026-27636Freescout unrestricted file upload vulnerabilityFreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Prior to version 1.8.206, FreeScout's file upload restriction list…EPSS 2.1%8.6CVE-2025-58163Freescout deserialization of untrusted data vulnerabilityFreeScout is a free help desk and shared inbox built with PHP's Laravel framework. Versions 1.8.185 and earlier contain a deserialization of untruste…EPSS 0.72%8.6CVE-2025-48389Freescout deserialization of untrusted data vulnerabilityFreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.178, FreeScout is vulnerable to deserialization of untrusted data …EPSS 0.91%

Source: NIST National Vulnerability Database (record CVE-2025-54366), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.