CVE-2026-20295
HighCVSS 8.6Exploitation Probability (EPSS)
Low risk45th percentile - higher than 45% of all known CVEs
Summary
Vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC and FTD Software allows an unauthenticated, remote attacker to exhaust the available memory of an affected device. This is due to improper management of memory resources during sftunnel TLS connection setup.
Risk Assessment
The attack can lead to memory exhaustion and a DoS condition, potentially causing device unavailability and network disruption.
Recommendation
Apply the software update from Cisco that fixes this vulnerability and monitor sftunnel traffic for anomalies.
Other vulnerabilities in Cisco Secure FMC/FTD Software
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS