CVE-2026-20323
Reported by cisco · Published September 16, 2026
A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software and Cisco Secure FTD Software could allow an unauthenticated, adjacent attacker to impersonate the peer device and obtain access at the level of the manager role, which is equivalent to root. This vulnerability is due to improper management of the TLS certificate for the sftunnel management connection. An attacker could exploit this vulnerability by connecting to the sftunnel port using a crafted TLS certificate. A successful exploit could allow the attacker to become a registered sftunnel peer with root access. Note: The attack is successful only if the sftunnel connection is down or the attack can disrupt the sftunnel connection long enough to execute the attack.
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Firewall Management Center (FMC) | 7.0.0, 7.0.0.1, 7.0.1 |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.0.0, 7.0.0.1, 7.0.1 |
| Cisco | Cisco Secure Firewall Management Center (FMC) | 7.0.10, 7.2.3, 7.2.3.1 |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.0.0.1, 7.0.1, 7.0.1.1 |
Timeline
- Sep 16, 2026 Coalition ESS Score
- Sep 16, 2026 CVE Published
- Sep 17, 2026 EPSS Score
- Sep 17, 2026 CVE Updated