YARPP – Yet Another Related Posts Plugin <= 5.30.3 - Authenticated (Contributor+) Stored Cross-Site Scripting

The YARPP plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 'className' parameter in versions up to, and including, 5.30.3 due to insufficient input sanitization and output escaping. This makes it possible for contributor-level attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.