Vulnerability · Published Jul 20, 2026 · Assigned by GitHub_M

CVE-2026-53592FreeScout vulnerable to prototype pollution in getQueryParam

Medium 4.6

In plain English

A medium-severity prototype pollution in freescout from freescout-help-desk. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 4% of all known vulnerabilities).

Severity (CVSS 3.1)4.6Medium

Exploit odds (30 days)0.1%top 96.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

Vendor	Product	Versions
freescout-help-desk	freescout	< 1.8.223

Weakness: CWE-1321 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L

References

https://github.com/freescout-help-desk/freescout/security/advisories/GHSA-w5fc-8pp3-f755 x_refsource_CONFIRM