Improper input validation in Cisco Adaptive Security Appliance Software
CVE-2026-20020
A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. If OSPF authentication is enabled, the attacker must know the secret key to exploit this vulnerability. This vulnerability is due to insufficient input validation when processing OSPF update packets. An attacker could exploit this vulnerability by sending crafted OSPF update packets. A successful exploit could allow the attacker to create a buffer overflow, causing the affected device to reload, resulting in a DoS condition.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.003 (16.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H.
Affected products
- Cisco Adaptive_security_appliance_software — versions 9.12.1, 9.12.1.2, 9.12.1.3
- Cisco Secure Firewall Adaptive Security Appliance (Asa) Software — versions 9.12.1, 9.12.1.2, 9.12.1.3
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 6.4.0, 6.4.0.1, 6.4.0.3
- Cisco Firepower_threat_defense — versions 6.4.0, 6.4.0.1, 6.4.0.2
- Cisco Secure_firewall_threat_defense — versions 6.4.0, 6.4.0.1, 6.4.0.2
Weakness classification (CWE)
References
- psirt@cisco.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20020?
- CVE-2026-20020 is a medium-severity vulnerability in Cisco Adaptive Security Appliance Software, classified under Improper Input Validation. CVSS score: 6.8/10. Published 2026-03-04.
- How severe is CVE-2026-20020?
- Medium severity. CVSS v3 base score is 6.8 out of 10.