#VU123548 Input validation error in Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC) and Cisco Firewall Threat Defense (FTD) - CVE-2026-20005
Published: March 4, 2026
Vulnerability identifier: #VU123548
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-2026-20005
CWE-ID: CWE-20
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 (DoS) attack.
The vulnerability exists due to insufficient parsing of the SSL handshake ingress packets by the Snort 3 Detection Engine. A remote attacker can send specially crafted SSL handshake packets to the system and perform a denial of service (DoS) attack.
Remediation
Install updates from vendor's website.