The ST Categories Widget plugin for WordPress suffers from a stored XSS vulnerability due to improper neutralization of input during web page generation (CWE-79). Specifically, the plugin fails to adequately sanitize and escape user-supplied attributes in the st-categories shortcode, allowing authenticated users with contributor or higher privileges to inject arbitrary JavaScript code. This code executes in the context of any user who views the compromised page, potentially leading to session hijacking or other client-side attacks. The vulnerability affects versions less than or equal to 1.0.0. No known exploits are reported in the wild, and no patch or remediation details have been provided.

An attacker with contributor-level or higher access can inject persistent malicious scripts into pages via the vulnerable shortcode. These scripts execute in the browsers of users who view the infected pages, potentially leading to information disclosure or session compromise. The impact is limited to confidentiality and integrity with no direct availability impact. The CVSS score of 6.4 reflects a medium severity level with network attack vector, low attack complexity, and no user interaction required.

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 disabling or removing the ST Categories Widget plugin if possible. Monitor for updates from the plugin vendor or WordPress plugin repository for a security patch addressing this vulnerability.