Infinite loop in Cisco Firewall Threat Defense (FTD) - CVE-2026-20054
Published: March 4, 2026
Vulnerability identifier: #VU123536
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-2026-20054
CWE-ID: CWE-835
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Cisco Systems, Inc
Affected software:
Cisco Firewall Threat Defense (FTD)
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 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.
How to mitigate CVE-2026-20054
Install updates from vendor's website.