#VU123536 Infinite loop in Cisco Firewall Threat Defense (FTD) - CVE-2026-20054
Published: March 4, 2026
Vulnerability identifier: #VU123536
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-2026-20054
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Cisco Firewall Threat Defense (FTD)
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 infinite loop in the Snort 3 VBA feature. A remote attacker can send specially crafted VBA data to the Snort 3 Detection Engine and perform a denial of service attack.
Remediation
Install updates from vendor's website.