The Ova Advent plugin for WordPress contains a stored cross‑site scripting flaw. In all versions up to and including 1.1.7 the plugin does not properly escape or sanitize user‑supplied shortcode attributes. An attacker with contributor‑level or higher permissions can insert arbitrary JavaScript. When a user visits the page that includes the malicious shortcode, the script runs in the victim’s browser with that user’s privileges, allowing cookie theft, session hijacking, phishing or defacement. This weakness is an instance of improper input validation (CWE‑87).

All WordPress sites that use the Ova Advent plugin version 1.1.7 or earlier are vulnerable. The plugin is distributed by ovatheme under the name Ova Advent. Administrators should verify the installed version and upgrade if it is affected.

The CVSS score of 6.4 indicates a medium severity, while the EPSS score of less than 1% reflects a very low current exploitation probability. The vulnerability is not listed in the CISA KEV catalog. Attackers must have authenticated contributor+ access, so the primary vector is an existing compromised account or insider. Once injected, any user who views the affected page can become a target, exposing session data or enabling further malicious actions. No public exploits are currently documented, but the low EPSS does not diminish the risk of exploitation in environments where contributor access is widespread.