The OPEN‑BRAIN WordPress plugin contains a stored cross‑site scripting flaw that arises from an insufficient sanitization routine for the 'API Key' setting field. The plugin calls sanitize_text_field() which removes HTML tags but leaves double quotes and other special characters intact, and later outputs the value into an input element’s value attribute without esc_attr() escaping. An administrator‑level user can therefore inject an attribute‑breakout payload such as a double quote followed by an event handler, which will be executed whenever any user opens the plugin settings page, potentially allowing the execution of arbitrary scripts in the victim’s browser context.

All instances of the OPEN‑BRAIN plugin for WordPress with versions up to and including 0.5.0, delivered by the vendor faridsaniee:OPEN‑BRAIN. No published fix version is indicated, so any deployment of these versions is potentially vulnerable.

The vulnerability has a CVSS score of 4.4, reflecting a moderate severity. EPSS Score is <1% and it is not listed in the CISA Known Exploited Vulnerabilities catalog. The attack can be carried out only by authenticated users with Administrator privileges, who can access the settings page, inject the payload, and trigger its execution on subsequent visits by other users. Because unauthenticated users cannot inject the payload, the risk is confined to environments where the attacker can obtain admin credentials or social‑engineer an admin user.