CVE-2026-20295

High

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.

SeverityHigh
CVSS8.6
Exploit probability—
ProductCisco Secure Firewall Management Center (FMC)
PublishedSep 16, 2026
First seenSep 16, 2026
Weakness typeCWE-789CWE-789

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Cisco Cisco Secure Firewall Management Center (FMC)7.0.0, 7.0.0.1, 7.0.1, 7.0.1.1, 7.0.2, 7.2.0, 7.0.2.1, 7.0.3, 7.2.0.1, 7.0.4, 7.2.1, 7.0.5, 7.3.0, 7.2.2, 7.3.1, 7.2.3, 7.2.3.1, 7.2.4, 7.0.6, 7.2.4.1, 7.2.5, 7.3.1.1, 7.4.0, 7.0.6.1, 7.2.5.1, 7.4.1, 7.2.6, 7.4.1.1, 7.0.6.2, 7.2.7, 7.2.5.2, 7.3.1.2, 7.2.8, 7.6.0, 7.4.2, 7.2.8.1, 7.0.6.3, 7.4.2.1, 7.2.9, 7.0.7, 7.7.0, 7.4.2.2, 7.2.10, 7.6.1, 7.4.2.3, 7.0.8, 7.6.2, 7.7.10, 7.2.10.1, 7.0.8.1, 7.6.2.1, 7.2.10.2, 7.7.10.1, 7.4.2.4, 7.4.3, 7.6.3, 7.7.11, 7.6.4, 10.0.0, 7.4.4, 7.4.5, 7.0.9, 7.2.11, 7.7.12, 7.6.5, 7.4.6, 10.0.1—
Cisco Cisco Secure Firewall Threat Defense (FTD) Software7.0.0, 7.0.0.1, 7.0.1, 7.0.1.1, 7.0.2, 7.2.0, 7.0.2.1, 7.0.3, 7.2.0.1, 7.0.4, 7.2.1, 7.0.5, 7.3.0, 7.2.2, 7.2.3, 7.3.1, 7.2.4, 7.0.6, 7.2.5, 7.2.4.1, 7.3.1.1, 7.4.0, 7.0.6.1, 7.2.5.1, 7.4.1, 7.2.6, 7.0.6.2, 7.4.1.1, 7.2.7, 7.2.5.2, 7.3.1.2, 7.2.8, 7.6.0, 7.4.2, 7.2.8.1, 7.0.6.3, 7.4.2.1, 7.2.9, 7.0.7, 7.7.0, 7.4.2.2, 7.2.10, 7.6.1, 7.4.2.3, 7.0.8, 7.6.2, 7.7.10, 7.7.11, 7.0.8.1, 7.6.2.1, 7.7.10.1, 7.4.2.4, 7.2.10.2, 7.4.3, 7.6.4, 10.0.0, 7.4.4, 7.0.9, 7.2.11—

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