Vulnerability · Published Sep 16, 2026 · Assigned by cisco
CVE-2026-20295Cisco Secure Firewall Management Center and Secure Firewall Threat Defense Software sftunnel Memory Exhaustion Denial of Service Vulnerability
High 8.6
In plain English
A high-severity security flaw in Cisco Secure Firewall Management Center (FMC) from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Official description
A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to exhaust the available memory of an affected device. This vulnerability is due to improper management of memory resources during sftunnel TLS connection setup. An attacker could exploit this vulnerability by sending crafted sftunnel TLS frames to an affected device during the connection setup. A successful exploit could allow the attacker to exhaust the available memory on the affected device, which could result in a DoS condition.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Firewall Management Center (FMC) | 7.0.07.0.0.17.0.17.0.1.17.0.27.2.07.0.2.17.0.3 |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.0.07.0.0.17.0.17.0.1.17.0.27.2.07.0.2.17.0.3 |
Weakness: CWE-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H