rules/wordpress-plugin-security.md

WordPress plugin security

• Check a capability with current_user_can(), not a role name. Use edit_shop_orders, edit_products, or manage_woocommerce for shop operations.
• Verify a nonce on cookie-authenticated state changes. A nonce does not authenticate the user and does not belong on a server-to-server webhook.
• Unslash request data, sanitize it to a known type, and escape on output for the HTML, attribute, or URL context you are writing.
• Pass SQL values through $wpdb->prepare(). Never build a table name or filesystem path from request input.
• Give every private REST route a permission_callback that checks a capability. Do not use __return_true for order, customer, or payment data.
• Authorize the specific object after you load it. A posted order id is not proof that this user may edit that order.
• Store structured meta as JSON or scalars. Do not unserialize() request data.
• Keep secrets, card data, and full $_POST payloads out of logs and order notes.