Vulnerability in Cisco Secure Firewall Adaptive Security Appliance (Asa) Software
CVE-2026-20039
A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service…
EPSS: 0.001 (25.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Cisco Secure Firewall Adaptive Security Appliance (Asa) Software — versions 9.12.3, 9.12.1, 9.12.2
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 6.4.0.1, 6.4.0.2, 6.4.0.5
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-20039?
- CVE-2026-20039 is a high-severity vulnerability in Cisco Secure Firewall Adaptive Security Appliance (Asa) Software, classified under CWE-244. CVSS score: 8.6/10. Published 2026-03-04.
- How severe is CVE-2026-20039?
- High severity. CVSS v3 base score is 8.6 out of 10.