Cisco moved swiftly to patch two severe vulnerabilities uncovered in its Secure Firewall Management Center (FMC) software that actors could have used to gain root access.

A total of two vulnerabilities were identified that would have allowed attackers to execute scripts and commands that allow root access to the device.

The first, tracked as CVE-2026-20079, stemmed from an issue where “an improper system process that is created at boot time.” Attackers could have exploited the issue by sending crafted HTTP requests to affected devices, allowing them to bypass authentication.

The second, tracked as CVE-2026-20131, was brought on by insecure deserialization of a user-supplied Java byte stream.

For those not versed in cybersecurity speak, deserialization is when a system restores data. In cases of insecure deserialization, that’s where a platform takes that assembly information without properly checking if it has been tampered with, allowing actors to sneak in malicious instructions that can give them unauthorized access to the system.

The issue in Cisco’s FMC meant an attacker could exploit such a vulnerability to execute arbitrary code on a device running the software.

Both vulnerabilities were given the highest possible severity score and have since been patched via a software update. Cisco confirmed that no other workarounds can address the issue.