CVE-2026-20007

A vulnerability in the Snort 2 and Snort 3 deep packet inspection of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured Snort rules and allow traffic onto the network that should have been dropped. This vulnerability is due to a logic error in the integration of the Snort Engine rules with Cisco Secure FTD Software that could allow different Snort rules to be hit when deep inspection of the packet is performed for the inner and outer connections. An attacker could exploit this vulnerability by sending crafted traffic to a targeted device that would hit configured Snort rules. A successful exploit could allow the attacker to send traffic to a network where it should have been denied.

Score

CVSS 3.1 5.8 Medium

Status

Analyzed - psirt@cisco.com

Published

2026-03-04

Last modified

2026-03-04

Weaknesses

CWE-284

Affected products

• Cisco Secure Firewall Threat Defense Ftd Software (Cisco)
• Secure Firewall Threat Defense (Cisco)

References

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort-bypass-rLggKzVF