CVE-2026-20016: Cisco Secure Firewall ASA and FTD command injection in FXOS CLI

CVE-2026-20016 · Severity: medium · CVSS 6 · Published 2026-03-04

A vulnerability in Cisco's firewall management software could allow a user with administrative access to bypass security restrictions and take full control of the underlying operating system. By entering specially crafted commands into the device's command-line interface, an attacker could gain root-level privileges, potentially leading to unauthorized data access or permanent modification of the security appliance. This issue affects specific Cisco Secure Firewall hardware, including the Firepower 2100, 4100, and 9300 series.

Technologies: Cisco Secure Firewall Threat Defense. Vendors: Cisco.

Quick answers

Is CVE-2026-20016 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-20016 being exploited in the wild.
How severe is CVE-2026-20016?
Medium severity, with a CVSS score of 6, published 4 March 2026.
Which products and versions are affected?
Cisco ASA Software 9.12.1 to 9.16.4.85, 9.17.1 to 9.18.4.66, 9.19.1 to 9.20.4, 9.22.1.1 to 9.22.2.4, 9.23.1 to 9.23.1.7; Cisco Secure Firewall Threat Defense 6.4.0 to 7.0.9, 7.1.0 to 7.2.11, 7.3.0 to 7.4.3, 7.6.0 to 7.6.4, 7.7.0 to 7.7.11.
Is there a fix for CVE-2026-20016?
A patch was published on 2026-03-04. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-20016 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-20016?
Check whether you run Cisco ASA Software, Cisco FXOS Software or Cisco Secure Firewall Threat Defense at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

This vulnerability (CVE-2026-20016) is classified as an argument injection flaw (CWE-88) within the Cisco FXOS Software CLI feature. The root cause is insufficient input validation of user-supplied command arguments for specific CLI commands. An attacker with valid administrative credentials can exploit this by submitting crafted input via a local terminal session. Successful exploitation allows the execution of arbitrary commands on the underlying Linux-based operating system with root privileges. The vulnerability specifically impacts Cisco Secure Firewall ASA and FTD software when running on Firepower 2100 (platform mode), 4100, and 9300 series appliances. Cisco has released software updates to address this issue; no workarounds are available.

Affected products

  • Cisco Secure Firewall ASA Software 9.12.1 to 9.16.4.85, 9.17.1 to 9.18.4.66, 9.19.1 to 9.20.4, 9.22.1.1 to 9.22.2.4, 9.23.1 to 9.23.1.7
  • Cisco Secure Firewall Threat Defense (FTD) Software 6.4.0 to 7.0.9, 7.1.0 to 7.2.11, 7.3.0 to 7.4.3, 7.6.0 to 7.6.4, 7.7.0 to 7.7.11
  • Cisco FXOS Software

Timeline

  • 2026-03-04: advisory: Initial advisory published by Cisco
  • 2026-03-04: disclosed
  • 2026-03-04: patched

References

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