CVE-2026-20021
Last modified
CVE-2026-20021 is a medium-severity vulnerability rated 4.3/10 on the CVSS scale. 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. EPSS estimates a 0.21% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Adaptive Security Appliance Software | >= 9.12.1, <= 9.12.4.67 |
| Cisco | Adaptive Security Appliance Software | >= 9.16.1, <= 9.16.4.85 |
| Cisco | Adaptive Security Appliance Software | >= 9.17.1, <= 9.17.1.46 |
| Cisco | Adaptive Security Appliance Software | >= 9.18.1, <= 9.18.4.68 |
| Cisco | Adaptive Security Appliance Software | >= 9.19.1, <= 9.19.1.42 |
| Cisco | Adaptive Security Appliance Software | >= 9.20.1, <= 9.20.4.14 |
| Cisco | Adaptive Security Appliance Software | >= 9.22.1.1, <= 9.22.2.14 |
| Cisco | Adaptive Security Appliance Software | >= 9.23.1, <= 9.23.1.22 |
| Cisco | Secure Firewall Threat Defense | 6.4.0 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.1 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.2 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.3 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.4 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.5 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.6 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.7 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.8 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.9 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.10 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.11 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.12 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.13 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.14 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.15 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.16 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.17 |
| Cisco | Secure Firewall Threat Defense | 6.4.0.18 |
| Cisco | Secure Firewall Threat Defense | 7.0.0 |
| Cisco | Secure Firewall Threat Defense | 7.0.0.1 |
| Cisco | Secure Firewall Threat Defense | 7.0.1 |
| Cisco | Secure Firewall Threat Defense | 7.0.1.1 |
| Cisco | Secure Firewall Threat Defense | 7.0.2 |
| Cisco | Secure Firewall Threat Defense | 7.0.2.1 |
| Cisco | Secure Firewall Threat Defense | 7.0.3 |
| Cisco | Secure Firewall Threat Defense | 7.0.4 |
| Cisco | Secure Firewall Threat Defense | 7.0.5 |
| Cisco | Secure Firewall Threat Defense | 7.0.6 |
| Cisco | Secure Firewall Threat Defense | 7.0.6.1 |
| Cisco | Secure Firewall Threat Defense | 7.0.6.2 |
| Cisco | Secure Firewall Threat Defense | 7.0.6.3 |
| Cisco | Secure Firewall Threat Defense | 7.0.7 |
| Cisco | Secure Firewall Threat Defense | 7.0.8 |
| Cisco | Secure Firewall Threat Defense | 7.0.8.1 |
| Cisco | Secure Firewall Threat Defense | 7.1.0 |
| Cisco | Secure Firewall Threat Defense | 7.1.0.1 |
| Cisco | Secure Firewall Threat Defense | 7.1.0.2 |
| Cisco | Secure Firewall Threat Defense | 7.1.0.3 |
| Cisco | Secure Firewall Threat Defense | 7.2.0 |
| Cisco | Secure Firewall Threat Defense | 7.2.0.1 |
| Cisco | Secure Firewall Threat Defense | 7.2.1 |
Showing 50 of 84 affected configurations. See NVD for the full list.
References
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
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