Vulnerability · 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 attacke…
Published Mar 4, 2026 · corrected/updated Aug 20, 2026 · cisco secure firewall threat defense · evidence confidence high
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.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-20007 is a medium public vulnerability record for cisco secure firewall threat defense. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether cisco secure firewall threat defense is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: cisco/secure firewall threat defense (6.4.0); cisco/secure firewall threat defense (6.4.0.1); cisco/secure firewall threat defense (6.4.0.2); cisco/secure firewall threat defense (6.4.0.3). Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 5.8, EPSS 0.2%. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-284. Sources contributing to this record: cve_org, epss, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in CISA KEV or VulnCheck KEV.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Mar 4, 2026 · NIST NVD
Detected
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 al
Aug 20, 2026 · NIST NVD
Updated
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 al
Affected
- cpe cisco/secure firewall threat defense6.4.0
- cpe cisco/secure firewall threat defense6.4.0.1
- cpe cisco/secure firewall threat defense6.4.0.2
- cpe cisco/secure firewall threat defense6.4.0.3
- cpe cisco/secure firewall threat defense6.4.0.4
- cpe cisco/secure firewall threat defense6.4.0.5
- cpe cisco/secure firewall threat defense6.4.0.6
- cpe cisco/secure firewall threat defense6.4.0.7
Sources
- CVE.orgVulnerability recordCVE-2026-20007
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-20007
30-day exploitation probability 0.2%
first.org - NIST NVDVulnerability recordCVE-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 vuln
nvd.nist.gov