Multiple Cisco products are affected by a vulnerability in the Snort 3 NetFlow Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete error checking when Snort 3 parses UDP Netflow Protocol packets. An attacker could exploit this vulnerability by sending a single crafted Netflow packet through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a 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
  • Cisco Open Source Snort3
  • Cisco Secure Firewall Threat Defense (ftd) Software
  • Cisco Utd Snort Ips Engine Software
  • Secure Firewall Threat Defense

No data.

No data.

References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-misc-dos-6mB22qAK cve-icon cve-icon
History

Thu, 22 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Thu, 22 Oct 2026 13:45:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco cisco Open Source Snort3
Cisco cisco Secure Firewall Threat Defense (ftd) Software
Cisco cisco Utd Snort Ips Engine Software
Cisco secure Firewall Threat Defense
Vendors & Products Cisco
Cisco cisco Open Source Snort3
Cisco cisco Secure Firewall Threat Defense (ftd) Software
Cisco cisco Utd Snort Ips Engine Software
Cisco secure Firewall Threat Defense

Wed, 21 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
Description Multiple Cisco products are affected by a vulnerability in the Snort 3 NetFlow Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete error checking when Snort 3 parses UDP Netflow Protocol packets. An attacker could exploit this vulnerability by sending a single crafted Netflow packet through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a DoS condition.
Title Multiple Cisco Products Snort 3 Netflow Denial of Service Vulnerabilities
Weaknesses CWE-835
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: 2026-10-21T16:12:20.285Z

Updated: 2026-10-22T19:10:53.022Z

Reserved: 2025-10-08T11:59:15.351Z

Link: CVE-2026-20019

cve-icon Vulnrichment

Updated: 2026-10-22T13:37:33.077Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-21T17:18:26.890

Modified: 2026-10-22T14:17:39.840

Link: CVE-2026-20019

cve-icon Redhat

No data.