The WP Meteor Website Speed Optimization Addon plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Author Name in all versions up to, and including, 3.4.18 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The payload is delivered via the comment author name field, which must clear WordPress's comment moderation workflow before being displayed, though this represents a display prerequisite rather than any sanitization control.