#VU123658 Resource exhaustion in Cisco Adaptive Security Appliance (ASA) and Cisco Firewall Threat Defense (FTD) - CVE-2026-20021
Published: March 9, 2026
Vulnerability identifier: #VU123658
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-20021
CWE-ID: CWE-400
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerable software:
Cisco Adaptive Security Appliance (ASA)
Cisco Firewall Threat Defense (FTD)
Cisco Adaptive Security Appliance (ASA)
Cisco Firewall Threat Defense (FTD)
Software vendor:
Cisco Systems, Inc
Cisco Systems, Inc
Description
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to application does not properly control consumption of internal resources when handling OSPF packets. A remote attacker on the local network can send specially crafted OSPF packets to an affected device, trigger memory exhaustion and perform a denial of service (DoS) attack.
Remediation
Install updates from vendor's website.