XSS exists in the shortcode functionality of the GistPress plugin before 3.0.2 for WordPress via the includes/class-gistpress.php id parameter. This allows an attacker with the WordPress Contributor role to execute arbitrary JavaScript code with the privileges of other users (e.g., ones who have the publish_posts capability).
https://wpvulndb.com/vulnerabilities/10053
https://github.com/bradyvercher/gistpress/releases/tag/v3.0.2
https://github.com/bradyvercher/gistpress/commit/e3f260edb6673227b0471c74b7ab13c094411ef7