The My YouTube Channel plugin for WordPress is vulnerable to Stored Cross-Site Scripting via its settings parameters in versions up to, and including, 3.0.12.1 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
https://www.wordfence.com/threat-intel/vulnerabilities/id/d979f899-8cdc-4230-b1b5-865c025dc86a