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

Severity
Medium 4.3
CVSS 3.1
Exploited
Not listed
EPSS
0.002
11.6th percentile
Discovered by
Vendor
Published by the vendor
Published
Mar 4, 2026
Assigned by cisco

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) Firewall / NGFW cna-assigner
Cisco Cisco Secure Firewall Firewall / NGFW cna-assigner
Vendor-reported affected versions (2)
  • Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
  • Cisco · Cisco Secure Firewall Threat Defense (FTD) Software