The Mixed Media Gallery Blocks plugin for WordPress, specifically the Gallery Blocks with Lightbox, Image Gallery, and Video Gallery components, suffers from a stored cross-site scripting vulnerability (CWE-79) via the gallery link text parameter. This occurs due to inadequate sanitization and escaping of user input, allowing authenticated users with Editor or higher privileges to inject malicious scripts. These scripts execute in the context of users who access the compromised pages, potentially leading to session hijacking or other script-based attacks. The vulnerability affects all versions up to and including 3.2.4.2. There is no vendor advisory or patch link provided, and the plugin is not a cloud service, so remediation depends on vendor updates or user action.

An attacker with Editor-level or higher access can inject persistent malicious scripts into pages via the gallery link text parameter. These scripts execute in the browsers of users who view the infected pages, potentially compromising user sessions or performing unauthorized actions within the context of the affected site. The confidentiality and integrity of user interactions may be impacted, but availability is not affected. The CVSS score of 5.5 reflects a medium severity level with network attack vector, low attack complexity, and required privileges.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict Editor-level access to trusted users only and consider disabling or removing the affected plugin to prevent exploitation. Monitor for plugin updates from the vendor that address this vulnerability.