The Opti-Behavior – Self-Hosted Heatmaps, Session Recordings, Funnels, A/B Testing & Smart Insights plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via 'country_name' Location Parameter in all versions up to, and including, 1.9.2.1 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 heatmap recording endpoint accepts unauthenticated requests protected only by a nonce that any visitor can freely obtain via the public opti_behavior_refresh_nonces AJAX action, removing any practical barrier to injecting the malicious payload.