Description
Multiple Cisco products are affected by a vulnerability in the Snort 3 Generic Routing Encapsulation (GRE) 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 GRE packets. An attacker could exploit this vulnerability by sending a crafted GRE packet to a targeted device to be parsed by Snort. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a DoS condition.
Published: 2026-10-21
Score: 5.8 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Thu, 22 Oct 2026 15:30:00 +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

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'}

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 Generic Routing Encapsulation (GRE) 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 GRE packets. An attacker could exploit this vulnerability by sending a crafted GRE packet to a targeted device to be parsed by Snort. 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 Generic Routing Encapsulation Denial of Service Vulnerabilities
Weaknesses CWE-128
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'}

Subscriptions

Cisco Cisco Open Source Snort3 Cisco Secure Firewall Threat Defense (ftd) Software Cisco Utd Snort Ips Engine Software Secure Firewall Threat Defense
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-10-22T19:11:03.271Z

Reserved: 2025-10-08T11:59:15.393Z

Link: CVE-2026-20179

cve-icon Vulnrichment

Updated: 2026-10-22T13:37:19.670Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-21T17:18:27.340

Modified: 2026-10-22T14:17:40.290

Link: CVE-2026-20179

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-22T14:57:25Z

Weaknesses