CVE-2026-20007 MEDIUM

CVE-2026-20007: Cisco Secure Firewall Threat Defense Software Snort Deep Inspection Bypass Vulnerability

Vendor Cisco
Product Cisco Secure Firewall Threat Defense (FTD) Software
Weakness CWE-284
Published March 4, 2026
Last update March 4, 2026

CVSS base score

5.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 4, 2026 CVE published
March 4, 2026 Record updated