Multiple vulnerabilities in the web-based management interface of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. These vulnerabilities are due to insufficient validation of user-supplied input by the web-based management interface. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or access sensitive, browser-based information.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-xss-6VqH4rpZ