The Custom User Registration Fields for WooCommerce plugin for WordPress is vulnerable to Privilege Escalation in versions up to, and including, 2.2.3. This is due to the plugin accepting an attacker-controlled afreg_select_user_role value from the unauthenticated WooCommerce Store API /wc/store/v1/checkout request in the af_reg_checkout_data_to_order_meta_data_block() function, persisting it in order meta, and then passing it directly to WP_User::add_role() in the af_reg_custom_order_processing_function() function (hooked to woocommerce_thankyou) without validating against the plugin's admin-configured allowed role list. This makes it possible for unauthenticated attackers to elevate their privileges to Administrator by creating an account during checkout with a modified JSON body specifying administrator (or any other role slug) as the desired role. Note: The exploit requires the "User Role Selection" setting to be enabled.

CVE-2026-15369 affects the Custom User Registration Fields for WooCommerce WordPress plugin in versions up to and including 2.2.3. The vulnerability allows unauthenticated attackers to escalate privileges to Administrator level by manipulating the afreg_select_user_role parameter in the WooCommerce Store API checkout request. The flaw exists because the plugin fails to validate the attacker-controlled role value against the admin-configured allowed role list before passing it to WP_User::add_role(). An attacker can exploit this during the checkout process by submitting a modified JSON body specifying 'administrator' or any other role slug. The exploit is conditional on the 'User Role Selection' setting being enabled in the plugin configuration. The vulnerability resides in the af_reg_checkout_data_to_order_meta_data_block() and af_reg_custom_order_processing_function() functions. No authentication is required to exploit this vulnerability, making it particularly dangerous for affected WordPress/WooCommerce installations.