In Splunk Enterprise versions below 8.1.12, 8.2.9, and 9.0.2, Splunk Enterprise fails to properly validate and escape the Host header, which could let a remote authenticated user conduct various attacks against the system, including cross-site scripting and cache poisoning.
https://www.splunk.com/en_us/product-security/announcements/svd-2022-1102.html