CVE-2026-20197
Multiple Cisco Products Snort 3 Teredo Protocol Denial of Service Vulnerability
MEDIUM 5.8
At a glance
- Source
- NVD
- EPSS
- EPSS 0.50 % · percentile 42 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- cisco
- NVD status
- Awaiting Analysis
Description
Multiple Cisco products are affected by a vulnerability in the Snort 3 Teredo 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 Teredo packets. An attacker could exploit this vulnerability by sending a crafted Teredo 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.
Weaknesses (CWE)
- CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L | cisco |
| CVSS 3.1 | MEDIUM 5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L | NVD · psirt@cisco.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-107376
- GCVE · GCVE-0-2026-20197
Affected products
| Product | Versions |
|---|---|
| Cisco · Cisco Open Source Snort3 | affected 3.12.2.0 ; affected 3.1.2.0 ; affected 3.1.3.0 ; affected 3.1.4.0 ; affected 3.1.5.0 ; affected 3.1.6.0 |
| Cisco · Cisco Secure Firewall Threat Defense (FTD) Software | affected 7.0.0 ; affected 7.0.0.1 ; affected 7.0.1 ; affected 7.0.1.1 ; affected 7.0.2 ; affected 7.2.0 |
| Cisco · Cisco UTD SNORT IPS Engine Software | affected 17.12.1a ; affected 17.12.2 ; affected 17.13.1a ; affected 17.12.3 ; affected 17.14.1a ; affected 17.12.4 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |