Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability

CVE-2026-20079 is a critical authentication bypass vulnerability affecting Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management. The flaw allows an unauthenticated remote attacker to bypass authentication mechanisms via an alternate path or channel. Successful exploitation enables the attacker to execute script files on the affected device, ultimately achieving root access to the underlying operating system. The vulnerability is classified as high criticality and is listed under CISA's BOD 26-04 directive, which prioritizes security updates based on risk. Organizations using Cisco FMC or SCC are urged to apply patches immediately. Forensic triage requirements have also been outlined by CISA for affected systems. The vulnerability is tracked in the NVD and has a dedicated Cisco Security Advisory.