#VU123659 Out-of-bounds write in Cisco Adaptive Security Appliance (ASA) and Cisco Firewall Threat Defense (FTD) - CVE-2026-20022

 

#VU123659 Out-of-bounds write in Cisco Adaptive Security Appliance (ASA) and Cisco Firewall Threat Defense (FTD) - CVE-2026-20022

Published: March 9, 2026


Vulnerability identifier: #VU123659
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-20022
CWE-ID: CWE-787
Exploitation vector: Adjecent network
Exploit availability: No public exploit available
Vulnerable software:
Cisco Adaptive Security Appliance (ASA)
Cisco Firewall Threat Defense (FTD)
Software vendor:
Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error when OSPF canonicalization debug is enabled. A remote attacker on the local network can send specially crafted OSPF packets to the affected device, trigger an out-of-bounds write and perform a denial of service (DoS) attack.


Remediation

Install updates from vendor's website.

External links