What is CVE-2025-54366?

CVE-2025-54366 is a high-severity vulnerability in Freescout, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2025-07-26.

How severe is CVE-2025-54366?

High severity. CVSS v3 base score is 8.8 out of 10.

Deserialization in Freescout

CVE-2025-54366

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 auth…

Vulnerability class: Insecure Deserialization

EPSS: 0.010 (58.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Affected products

Freescout
Freescout-help-desk Freescout — versions < 1.8.186

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
security-advisories@github.com (Patch, x_refsource_MISC)

Frequently asked questions

What is CVE-2025-54366?: CVE-2025-54366 is a high-severity vulnerability in Freescout, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2025-07-26.
How severe is CVE-2025-54366?: High severity. CVSS v3 base score is 8.8 out of 10.