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

Medium 5.8 Published 4 Mar 2026 Updated 4 Mar 2026

An unauthenticated remote attacker can bypass Snort deep packet inspection rules to send unauthorized traffic onto the network.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-20007?

CVE-2026-20007 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense, published on 4 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-284

Which versions are affected by CVE-2026-20007?

It affects 1 product.

Products include Cisco Secure Firewall Threat Defense.

How do I fix CVE-2026-20007?

No fix has been published for CVE-2026-20007 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-20007 being exploited?

There is no known exploitation of CVE-2026-20007 in the wild and no public exploit code.

All Cisco Secure Firewall Threat Defense vulnerabilities

Sources

Also known as GHSA-33pq-q8j2-pf3g.