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 unexpec
Description
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.
Weakness: CWE-20
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Check your version | Firewall / NGFW | cna-assigner |
| Cisco | Cisco Firepower Threat Defense (FTD) Check your version | Firewall / NGFW | cna-assigner |
Vendor-reported products (2)
- Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
- Cisco · Cisco Secure Firewall Threat Defense (FTD) Software
Vendor advisory
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software OSPF Protocol Vulnerabilities
Cisco’s rating: Medium (advisory CVSS 6.8) · Published Mar 4, 2026
Bug IDs: CSCwn69075 , CSCwn69076 , CSCwn69078 , CSCwn69079 , CSCwn69081 , CSCwo71552 , CSCwq73656
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from