There is a stored Cross-site Scripting vulnerability in Esri Portal for ArcGIS Enterprise Sites versions 10.8.1 – 11.1 that may allow a remote, authenticated attacker to create a crafted link that is stored in the site configuration which when clicked could potentially execute arbitrary JavaScript code in the victims browser.  The privileges required to execute this attack are high. The impact to Confidentiality, Integrity and Availability are High.