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.
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53592.json",
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-1321"
]
}