Add-cart.php — Num ((hot))

// Using PDO prepared statement $stmt = $pdo->prepare('SELECT stock FROM products WHERE id = ?'); $stmt->execute([$productId]);

// Fetch product from DB and check stock // ... add-cart.php num

session_start(); if (!isset($_SESSION['user_id'])) // Redirect to login or use guest cart add-cart.php num

Never trust the num parameter. Sanitize it immediately: add-cart.php num

The add-cart.php script is often a blind spot for session management. Attackers combine num injection with .