VulnerabilityDeferred

CVE-2026-53592

As a result, an attacker-controlled URL query string can still write into `Object.prototype` on any page that loads `main.js`.

MEDIUM 4.6EPSS 0.19%

Does this matter?

Lower severity and a low EPSS score (0.19%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 4.6 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:L
EPSS: 0.19% probability · 9th percentile
CISA KEV: Not listed
Weakness: CWE-1321
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.