A vulnerability in the RADIUS subsystem implementation of Cisco Secure Firewall Management Center (FMC) Software could allow an unauthenticated, remote attacker to inject arbitrary shell commands that are executed by the device.  This vulnerability is due to a lack of proper handling of user input during the authentication phase. An attacker could exploit this vulnerability by sending crafted input when entering credentials that will be authenticated at the configured RADIUS server. A successful exploit could allow the attacker to execute commands at a high privilege level. Note: For this vulnerability to be exploited, Cisco Secure FMC Software must be configured for RADIUS authentication for the web-based management interface, SSH management, or both. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-radius-rce-TNBKf79 This advisory is part of the August 2025 release of the Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: August 2025 Semiannual Cisco Secure Firewall ASA, Secure FMC, and Secure FTD Software Security Advisory Bundled Publication.