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: 6.9 [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]
CVE-ID: CVE-2026-20005
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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.
Affected software
Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC)
Cisco Firewall Threat Defense (FTD)
Cisco Firewall Threat Defense (FTD)
How to mitigate CVE-2026-20005
Install updates from vendor's website.
Cisco Secure Firewall Management Center (formerly Firepower Management Center, FMC) - addressed in versions 7.6.4, 7.7.11
Cisco Firewall Threat Defense (FTD) - addressed in versions 7.6.4, 7.7.11
Cisco Firewall Threat Defense (FTD) - addressed in versions 7.6.4, 7.7.11