The Ultimate Member WordPress plugin was vulnerable to an Unauthenticated Open Redirect vulnerability, affecting the registration and login pages where the "redirect_to" GET parameter was used.
https://www.example.com/register/?redirect_to=https://www.evil.com/
2020-08-12 (about 2 years ago)
2020-08-12 (about 2 years ago)
2020-08-13 (about 2 years ago)