A potential vulnerability in Splunk Enterprise's implementation of DUO MFA allows for bypassing the MFA verification in Splunk Enterprise versions before 8.1.6. The potential vulnerability impacts Splunk Enterprise instances configured to use DUO MFA and does not impact or affect a DUO product or service.
https://www.splunk.com/en_us/product-security/announcements/svd-2022-0504.html