CVE-2026-20007
Cisco Secure Firewall Threat Defense Software Snort Deep Inspection Bypass Vulnerability
At a glance Severity MEDIUM 5.8 EPSS EPSS 0.25 % · percentile 16 (2026-10-27) State PUBLISHED Published 2026-03-04 Updated 2026-03-04 Assigner cisco NVD status Analyzed Description 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.
Scores Version Score Vector Scored by CVSS 3.1 MEDIUM 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N cisco CVSS 3.1 MEDIUM 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N NVD · psirt@cisco.com (Secondary)
Weaknesses (CWE)
European references
Affected configurations (NVD CPE) cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.2:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.3:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.4:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.5:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.6:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.7:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.8:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.9:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.10:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.11:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.12:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.13:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.14:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.15:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.16:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.17:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:6.4.0.18:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.0.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.1.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.2.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.3:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.4:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.5:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6.2:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.6.3:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.7:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.8:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.0.8.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.2:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.1.0.3:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.2.0:*:*:*:*:*:*:*+33 more Affected products
References
Sources
