The Avada (Fusion) Builder WordPress plugin suffers from a stored cross-site scripting vulnerability (CWE-79) due to improper neutralization of input during web page generation. Specifically, user-supplied attributes in the plugin's shortcodes are not properly sanitized or escaped, allowing authenticated users with contributor or higher privileges to inject malicious scripts. These scripts execute in the context of any user who views the affected page, potentially leading to session hijacking or other script-based attacks. The vulnerability affects all versions up to 3.11.11. The CVSS 3.1 base score is 6.4 (medium), with network attack vector, low attack complexity, requiring privileges, no user interaction, and impacts on confidentiality and integrity with scope change.

An attacker with contributor-level or higher access can inject persistent malicious scripts into pages via shortcode attributes. These scripts execute in the browsers of users who view the compromised pages, potentially exposing sensitive information or enabling further attacks. The impact affects confidentiality and integrity but does not affect availability. There are no known exploits in the wild at this time.

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. Monitor for suspicious shortcode content and consider implementing additional input validation or output escaping at the application level if feasible.