Input validation error in Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC) and Cisco Firewall Threat Defense (FTD) - CVE-2026-20005

 

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
CSH Severity: Medium
CVSS v4.0: 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
Vendor: Cisco Systems, Inc
Affected software:
Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC)
Cisco Firewall Threat Defense (FTD)

Detailed vulnerability 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.


How to mitigate CVE-2026-20005

Install updates from vendor's website.

Sources