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.
EPSS 0.02% · 4.5th percentile
Risk Scores
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Firewall Adaptive Security Appliance (ASA) Software | 9.12.1, 9.12.1.2, 9.12.1.3 |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 6.4.0, 6.4.0.1, 6.4.0.3 |
Timeline
- Oct 8, 2025 CVE ID Reserved
- Mar 4, 2026 CVE Published
- Mar 4, 2026 PoC Published
- Mar 4, 2026 CVE Updated
- Mar 5, 2026 EPSS Score
- Mar 6, 2026 EPSS Score
- Mar 7, 2026 EPSS Score
- Mar 9, 2026 EPSS Score
- Mar 10, 2026 EPSS Score
- Mar 11, 2026 EPSS Score
- Mar 12, 2026 EPSS Score
- Mar 14, 2026 EPSS Score