CVE-2026-20323

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

Description An issue exists in the sftunnel inter-device communication protocol. An unauthenticated, adjacent attacker can impersonate a peer device to gain access with the manager role, which provides root-level privileges. This is caused by improper management of the TLS certificate used for the sftunnel management connection. An attacker can exploit this by connecting to the sftunnel port using a crafted TLS certificate, provided the sftunnel connection is down or can be disrupted long enough to execute the attack.

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