The Ultimate Member WordPress plugin before 2.13.1 does not escape a value derived from user supplied profile names before outputting it in the page title, and decodes HTML entities in it after its …

Summary

The Ultimate Member WordPress plugin before 2.13.1 does not escape a value derived from user supplied profile names before outputting it in the page title, and decodes HTML entities in it after its own sanitisation has already run, allowing unauthenticated attackers who register an account to store JavaScript that will execute when any visitor, including an administrator, views their profile.