Welcart e-Commerce <= 2.8.3 is vulnerable to Multiple Auth. Stored Cross-Site Scripting (XSS) vulnerabilities

The Welcart e-Commerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.8.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.