CVE-2026-20021
A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, adjacent
Description
A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, adjacent attacker to exhaust memory on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improperly validating input by the OSPF protocol when parsing packets. An attacker could exploit this vulnerability by by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to exhaust memory on the affected device, resulting in a DoS condition.
Weakness: CWE-401
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