The Happy Addons for Elementor plugin suffers from a stored XSS vulnerability via the '_id' parameter due to improper neutralization of input during web page generation (CWE-79). This allows authenticated users with Contributor or higher privileges to inject malicious scripts that execute in the context of other users viewing the compromised pages. The vulnerability impacts all versions up to 3.10.8. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, privileges required, no user interaction, and partial confidentiality and integrity impact.

An attacker with Contributor-level or higher access can inject persistent malicious scripts into pages, which execute when viewed by other users. This can lead to partial confidentiality and integrity compromise of user data within the affected WordPress environment. There is no indication of availability impact. No known exploits in the wild have been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, restrict Contributor-level access to trusted users only and consider monitoring or reviewing content changes involving the '_id' parameter. Avoid granting unnecessary privileges to reduce risk.