A vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 2 Detection Engine to restart. This vulnerability is due to incomplete validation of the SSL certificate. An attacker could exploit this vulnerability by sending a crafted SSL connection setup request to be parsed by Snort 2. A successful exploit could allow the attacker to cause the Snort 2 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.

Metrics

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable yes

Technical Impact partial

Affected Vendors & Products

Vendors Products
Cisco
  • Secure Firewall Threat Defense

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References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort2-ssldos-Mw7WYX9c cve-icon cve-icon
History

Fri, 18 Sep 2026 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco secure Firewall Threat Defense
Vendors & Products Cisco
Cisco secure Firewall Threat Defense

Thu, 17 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 16 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
Description A vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 2 Detection Engine to restart. This vulnerability is due to incomplete validation of the SSL certificate. An attacker could exploit this vulnerability by sending a crafted SSL connection setup request to be parsed by Snort 2. A successful exploit could allow the attacker to cause the Snort 2 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.
Title Cisco Secure Firewall Threat Defense Software Snort 2 SSL/TLS Denial of Service Vulnerability
Weaknesses CWE-805
References
Metrics cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L'}
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2026-09-16T20:19:02.761Z

Updated: 2026-09-17T17:29:41.938Z

Reserved: 2025-10-08T11:59:15.405Z

Link: CVE-2026-20290

cve-icon Vulnrichment

Updated: 2026-09-17T17:25:37.891Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-16T21:17:09.610

Modified: 2026-09-18T13:28:28.567

Link: CVE-2026-20290

cve-icon Redhat

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