The Cost Calculator Builder PRO plugin for WordPress is vulnerable to Remote Code Execution in all versions up to, and including, 4.0.3 via the js_to_php function. This is due to insufficient sanitization of the orderDetails[*].originalValue field, which is injected verbatim into a calculator formula string passed to PHP eval() inside js_to_php(), with the regex allow-list in evaluateFormula() only filtering alphanumeric tokens and leaving non-word punctuation characters intact. This makes it possible for unauthenticated attackers to execute code on the server. The only authentication barrier is a nonce check, but the required nonce is publicly emitted on every front-end page via the wp_head hook, making it freely obtainable by unauthenticated visitors. Payloads must be non-word XOR gadgets to bypass sanitization.