SendPulse Email Marketing Newsletter <= 2.2.5 - Authenticated (Contributor+) Stored Cross-Site Scripting via _sp_form_code Post Meta

The SendPulse Email Marketing Newsletter plugin for WordPress is vulnerable to Stored Cross-Site Scripting via _sp_form_code Post Meta in all versions up to, and including, 2.2.5 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires the attacker to create a sendpulse_form post containing a benign SendPulse loader script tag alongside arbitrary HTML (e.g., an img onerror payload), which bypasses the allow-list check and executes in the browser of any user — including administrators — who previews or views a page rendering the [sendpulse-form] shortcode.