CVE-2026-53592

MEDIUM

FreeScout vulnerable to prototype pollution in getQueryParam

Title source: cna
STIX 2.1

Description

FreeScout is a free help desk and shared inbox built with PHP's Laravel framework. A Prototype Pollution condition in the `getQueryParam` function `/public/js/main.js` and was addressed in version 1.8.139 by blocking URL query keys matching the pattern `__proto__`. However, this mitigation is incomplete: it only filters top-level `__proto__` keys and fails to sanitize nested forms such as `b[__proto__][polluted]=PWNED`. As a result, an attacker-controlled URL query string can still write into `Object.prototype` on any page that loads `main.js`. Version 1.8.223 contains a updated fix.

References (1)

Core 1

Scores

CVSS v3 4.6
EPSS 0.0012
EPSS Percentile 2.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact partial

Details

CWE
CWE-1321
Status published
Products (1)
freescout-help-desk/freescout < 1.8.223
Published Jul 20, 2026
Tracked Since Jul 21, 2026