Cisco firewall update includes two exploited FMC access flaws
NCSC-NL reports Cisco’s Secure Firewall hardening release covers eight vulnerability classes across ASA, Threat Defense and Management Center, while confirming active exploitation of two earlier FMC flaws. Four of the eight new CVEs have CVSS scores of 9.0 or higher; Cisco reports no known exploitation of the remaining flaws.
The two FMC flaws, CVE-2026-20079 and CVE-2026-20316, respectively let an attacker bypass authentication through an alternate route or gain access with hard-coded credentials. Either can get past the login barrier to FMC’s management interface, which is used to administer firewalls.
For teams using FMC to manage firewall estates, the exposure reaches the control plane, not just the appliance running it. The advisory does not say what attackers did after gaining access, so installing the fix alone cannot establish whether management was abused beforehand.