Next-Cart Store to WooCommerce Migration <= 3.9.8 - Unauthenticated Authentication Bypass via Default '__token__' Fallback in REST Migration Endpoint

The Next-Cart Store to WooCommerce Migration plugin for WordPress is vulnerable to Authentication Bypass in all versions up to, and including, 3.9.8 via the `NCWM_Kitconnect::run()` function. This is due to the plugin registering the `/wp-json/next_cart/v1/migration` REST route with `permission_callback` set to `__return_true` and relying on a hardcoded fallback value of `__token__` in `get_option('nextcart_token', '__token__')` when the `nextcart_token` option has not yet been written to the database. This makes it possible for unauthenticated attackers to bypass authentication to the migration endpoint by supplying the literal string `__token__` as the token, gaining access to privileged handlers that pass attacker-controlled SQL directly to `$wpdb->query()` and `$wpdb->get_results()` — enabling arbitrary SQL execution including administrator account creation — and pass an attacker-controlled path to `unlink()`, enabling arbitrary file deletion and full site takeover. The hardcoded fallback is reachable whenever the `nextcart_token` option has not yet been populated, which occurs after WP-CLI, network, or programmatic plugin activation without a subsequent authenticated `wp-admin` visit, as token generation is deferred to `admin_init` via `register_settings()`.

Quoted source text, attributed separately from HOL analysis.