The WPBakery Page Builder plugin for WordPress contains a stored XSS vulnerability (CWE-79) in its Grid Builder feature due to improper neutralization of user-supplied input during web page generation. Authenticated users with author-level privileges or above can inject arbitrary JavaScript code that executes in the context of any user visiting the affected page. This vulnerability affects all versions up to and including 8.4.1. The CVSS 3.1 base score is 6.4, reflecting a network attack vector, low attack complexity, required privileges at the author level, no user interaction, and impacts on confidentiality and integrity with no availability impact. No patch or official fix information is currently available.

Successful exploitation allows an authenticated author-level user to inject persistent malicious scripts into pages, which execute in the browsers of users who view those pages. This can lead to unauthorized actions performed on behalf of users, data theft, or session hijacking. The impact is limited to confidentiality and integrity, with no direct availability impact. Since the attacker must have author-level access, the risk is mitigated by existing access controls but remains significant within environments where such privileges are granted.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict author-level access to trusted users only and consider disabling or limiting use of the Grid Builder feature if feasible. Monitor vendor channels for updates and apply patches promptly once available.