CVE-2026-20341

Name of the Vulnerable Software and Affected Versions Cisco Secure FMC Software (affected versions not specified)

Description An issue exists in the sftunnel inter-device communication protocol that allows an authenticated remote attacker to obtain root privileges on a device running the software and its high-availability peer. The flaw stems from unsecured deserialization of untrusted data over the sftunnel management connection. An attacker with valid administrative credentials on a managed Cisco FTD device can exploit this by sending crafted sftunnel remote procedure calls (RPCs). Deserialization is the process of converting a data format, such as JSON or XML, back into an object that can be used by a program.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.