CVE-2026-20324

Critical

Description

A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, remote attacker to execute arbitrary commands as root. This vulnerability exists because a registered sftunnel peer has incorrect permissions to write an arbitrary file to any location on the device. An attacker could exploit this vulnerability by hijacking the sftunnel communication connection or being a valid registered sftunnel peer and sending an sftunnel command to write a malicious file to the disk of an affected device. A successful exploit could allow the attacker to write a file to the device that is executed with root privileges. To exploit this vulnerability, the attacker must have valid user credentials on the affected device.

SeverityCritical
CVSS9.9
Exploit probability—
ProductCisco Secure Firewall Management Center (FMC)
PublishedSep 16, 2026
First seenSep 16, 2026

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, 7.4.7—

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