Checkout Files Upload for WooCommerce 2.4.0 - Unauthenticated Stored XSS via Uploaded File

Description

The plugin does not verify that a file uploaded at checkout is really one of its allowed image types, and serves stored uploads inline using their detected content type, allowing unauthenticated users to upload an HTML file disguised as an image that executes JavaScript in the browser of a shop manager or administrator who opens it from the order screen.
This is a regression of CVE-2025-4212, reintroduced in 2.4.0.