Vulnerability in Cisco Secure Firewall Adaptive Security Appliance (Asa) Software
CVE-2026-20331
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense Software and Cisco Secure Firewall Management Center Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20331 are related to the failure of protection mechanisms issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-693.
CVSS v3 metric
CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L.
Affected products
- Cisco Secure Firewall Adaptive Security Appliance (Asa) Software — versions 9.16.1, 9.16.1.28, 9.16.2
- Cisco Secure Firewall Management Center (Fmc) — versions 10.0.0, 10.0.1, 7.0.0
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 10.0.0, 7.0.0.1, 7.0.1
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-20331?
- CVE-2026-20331 is a critical-severity vulnerability in Cisco Secure Firewall Adaptive Security Appliance (Asa) Software, classified under Protection Mechanism Failure. CVSS score: 9.6/10. Published 2026-09-16.
- How severe is CVE-2026-20331?
- Critical severity. CVSS v3 base score is 9.6 out of 10.