CVE-2026-20016
Cisco Adaptive Security Appliance Software 9.12.1 – 9.16.4.85
Raw vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-20016 is a medium-severity Argument Injection (CWE-88) vulnerability in Cisco Adaptive Security Appliance Software. Its CVSS base score is 6.0 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 26th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-9476
Vulnerability Data
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…
more
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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
—
V1.2.5
Mitigating Controls (NIST 800-53 r5) AI
Developer testing can discover argument-injection flaws in command-construction code but does not stop their introduction.
Input validation directly stops construction of command strings containing unneutralized delimiters or injected arguments.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require proper input validation and command construction to prevent argument injection.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing can detect argument injection but does not prevent it at the source.
Secure development lifecycle mandates input validation and command construction practices that directly prevent argument injection.
Application security requirements include explicit rules for safe command-line argument handling and escaping.
Secure architecture principles discourage unsafe command invocation patterns and favor safer APIs.
Secure coding standards explicitly require proper neutralization of command arguments, directly eliminating CWE-88.