Cisco Secure Firewall Threat Defense Software command injection

Summaryinfo

A vulnerability marked as critical has been reported in Cisco Secure Firewall Threat Defense Software. This affects an unknown function. Performing a manipulation results in command injection. This vulnerability is reported as CVE-2026-20016. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Cisco Secure Firewall Threat Defense Software (the affected version is unknown). This affects an unknown code. The manipulation with an unknown input leads to a command injection vulnerability. CWE is classifying the issue as CWE-77. The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A vulnerability in the Cisco FXOS Software CLI feature for Cisco Secure Firewall ASA Software and Secure FTD Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system with root-level privileges. To exploit this vulnerability, the attacker must have valid administrative credentials on an affected device. This vulnerability is due to insufficient input validation of user-supplied command arguments. An attacker could exploit this vulnerability by submitting crafted input for specific CLI commands. A successful exploit could allow the attacker to execute commands on the underlying operating system with root-level privileges.

It is possible to read the advisory at sec.cloudapps.cisco.com. This vulnerability is uniquely identified as CVE-2026-20016. The exploitability is told to be easy. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/06/2026). The attack technique deployed by this issue is T1202 according to MITRE ATT&CK.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-9476). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• Secure Firewall Threat Defense Software

License

• commercial

Website

• Vendor: https://www.cisco.com/

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Be aware that VulDB is the high quality source for vulnerability data.

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