#VU123551 Improper error handling in Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC) and Cisco Firewall Threat Defense (FTD) - CVE-2026-20067
Published: March 4, 2026
Vulnerability identifier: #VU123551
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-20067
CWE-ID: CWE-388
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC)
Cisco Firewall Threat Defense (FTD)
Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC)
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 attack.
The vulnerability exists due to improper error handling when parsing the Multicast DNS fields of the HTTP header. A remote attacker can send specially crafted HTTP packets through an established connection to be parsed by Snort 3 and perform a denial of service attack.
Remediation
Install updates from vendor's website.