CVE-2026-20324: Cisco Secure Firewall Management Center sftunnel Root Arbitrary Code Exectution Vulnerability

Published Sep 16, 2026
·
Updated

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.

Affected Software

1 affected component
Cisco Cisco Secure Firewall Management Center (FMC)

Event History

Sep 16, 2026
CVE Published
via MITRE·08:06 PM
Data Sourced
via MITRE·08:06 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What level of access does an attacker need to exploit this issue?

The attacker must have valid user credentials on the affected device. Exploitation also involves either hijacking an sftunnel communication connection or acting as a valid registered sftunnel peer.

2

What capability does successful exploitation provide?

A successful attacker can write a malicious file to the affected device that is then executed with root privileges. This enables arbitrary command execution as root.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203