The Stackable – Page Builder Gutenberg Blocks plugin for WordPress suffers from a stored cross-site scripting vulnerability due to improper neutralization of input in the 'data-caption' parameter. Authenticated users with Contributor or higher privileges can inject arbitrary JavaScript code into pages, which executes in the context of users who visit those pages. This vulnerability is present in all plugin versions up to 3.13.1. The CVSS 3.1 vector indicates network attack vector, low attack complexity, requiring privileges, no user interaction, and impacts confidentiality and integrity with no availability impact.

An attacker with Contributor-level or higher access can inject persistent malicious scripts into pages via the vulnerable parameter. These scripts execute in the browsers of users who view the compromised pages, potentially leading to data theft, session hijacking, or other client-side attacks. The vulnerability affects confidentiality and integrity but does not impact 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 released, restrict Contributor-level access to trusted users only and consider removing or disabling the Stackable plugin if possible. Monitor for plugin updates that address this vulnerability and apply them promptly once available.