Ultimate Member <= 2.8.3 is vulnerable to Unauthenticated Stored Cross-Site Scripting vulnerability

The Ultimate Member – User Profile, Registration, Login, Member Directory, Content Restriction & Membership Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the several parameters in all versions up to, and including, 2.8.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.