VDB
CVE-2026-20179
CVE-2026-20179
PUBLISHED
CVSS 5.8 MEDIUM
Reported by cisco · Published October 21, 2026
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.
Risk Scores
CVSS 3.1
5.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Open Source Snort3 | 3.12.2.0, 3.1.2.0, 3.1.3.0 |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.0.0, 7.0.0.1, 7.0.1 |
| Cisco | Cisco UTD SNORT IPS Engine Software | 17.12.1a, 17.12.2, 17.13.1a |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.0.0, 7.0.0.1, 7.0.1 |
| Cisco | Cisco Open Source Snort3 | 3.1.72.0, 3.1.73.0, 3.1.74.0 |
| Cisco | Cisco UTD SNORT IPS Engine Software | 17.12.1a, 17.12.2, 17.13.1a |
Timeline
- Oct 21, 2026 CVE Published
- Oct 22, 2026 EPSS Score
- Oct 22, 2026 Coalition ESS Score
- Oct 25, 2026 EPSS Score
- Oct 29, 2026 EPSS Score