CVE-2026-20341: Cisco Secure Firewall Management Center Software sftunnel Deserialization Root Command Execution Vulnerability
A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software could allow an authenticated, remote attacker to obtain root privileges. This vulnerability is due to unsecured deserialization of untrusted data over the sftunnel management connection. An attacker could exploit this vulnerability by sending crafted sftunnel remote procedure calls (RPCs). A successful exploit could allow the attacker to gain root privileges on a device that is running Cisco Secure FMC Software and its high-availability peer. To exploit this vulnerability, the attacker must have valid administrative credentials on a managed Cisco FTD device.
Affected Software
Event History
Frequently Asked Questions
What access does an attacker need before exploiting this issue?
The attacker must have valid administrative credentials on a managed Cisco FTD device. Exploitation is remote and uses crafted sftunnel RPCs over the sftunnel management connection.
What systems could be affected by a successful exploit?
A successful exploit can give the attacker root privileges on the Cisco Secure FMC Software device and its high-availability peer.