CVE-2026-0916 describes a stored cross-site scripting vulnerability in the Related Posts by Taxonomy plugin for WordPress. The flaw exists in the handling of the 'related_posts_by_tax' shortcode, where user input is not properly sanitized or escaped before being output in web pages. This allows authenticated users with contributor or higher roles to inject arbitrary JavaScript code that executes in the context of other users viewing the page. The vulnerability affects all plugin versions up to and including 2.7.6. The CVSS 3.1 base score is 6.4, reflecting network attack vector, low attack complexity, privileges required, no user interaction, and partial impact on confidentiality and integrity.

An attacker with contributor-level or higher access can exploit this vulnerability to inject malicious scripts into pages via the shortcode attributes. These scripts execute in the browsers of users who visit the injected pages, potentially leading to session hijacking, defacement, or other client-side attacks. The vulnerability 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 disabling or removing the Related Posts by Taxonomy plugin if possible to reduce risk.