p PatchFirst

CVE-2026-20197

CVE-2026-20197 · Multiple Cisco Products Snort 3 Teredo Protocol Denial of Service Vulnerability

This page contains facts from public vulnerability sources. Check the original advisory before updating.

This page shows selected source facts. See the linked advisories for the complete description and affected versions.

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.

CVSS 5.8 · Medium · EPSS 0.4%

Published
Updated

Affected products and versions

  • cisco open source snort3

    Versions
    • 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: Affected
    • 3.1.7.0: Affected
    • 3.1.8.0: Affected
    • 3.1.9.0: Affected
    • 3.1.10.0: Affected
    • 3.1.12.0: Affected
    • 3.1.13.0: Affected
    • 3.1.14.0: Affected
    • 3.1.15.0: Affected
    • 3.1.16.0: Affected
    • 3.1.17.0: Affected
    • 3.1.18.0: Affected
    • 3.1.19.0: Affected
    • 3.1.20.0: Affected
    • 3.1.21.0: Affected
    • 3.1.22.0: Affected
    • 3.1.23.0: Affected
    • 3.1.24.0: Affected
    • 3.1.25.0: Affected
    • 3.1.27.0: Affected
    • 3.1.28.0: Affected
    • 3.1.29.0: Affected
    • 3.1.30.0: Affected
    • 3.1.31.0: Affected
    • 3.1.32.0: Affected
    • 3.1.36.0: Affected
    • 3.1.38.0: Affected
    • 3.1.39.0: Affected
    • 3.1.40.0: Affected
    • 3.1.41.0: Affected
    • 3.1.42.0: Affected
    • 3.1.43.0: Affected
    • 3.1.45.0: Affected
    • 3.1.47.0: Affected
    • 3.1.48.0: Affected
    • 3.1.50.0: Affected
    • 3.1.51.0: Affected
    • 3.1.52.0: Affected
    • 3.1.53.0: Affected
    • 3.1.55.0: Affected
    • 3.1.56.0: Affected
    • 3.1.57.0: Affected
    • 3.1.58.0: Affected
    • 3.1.59.0: Affected
    • 3.1.60.0: Affected
    • 3.1.61.0: Affected
    • 3.1.62.0: Affected
    • 3.1.63.0: Affected
    • 3.1.64.0: Affected
    • 3.1.65.0: Affected
    • 3.1.66.0: Affected
    • 3.1.67.0: Affected
    • 3.1.69.0: Affected
    • 3.1.70.0: Affected
    • 3.1.71.0: Affected
    • 3.1.72.0: Affected
    • 3.1.73.0: Affected
    • 3.1.74.0: Affected
    • 3.1.75.0: Affected
    • 3.1.76.0: Affected
    • 3.1.77.0: Affected
    • 3.1.78.0: Affected
    • 3.1.81.0: Affected
    • 3.1.82.0: Affected
    • 3.1.83.0: Affected
    • 3.1.84.0: Affected
    • 3.2.1.0: Affected
    • 3.2.2.0: Affected
    • 3.3.0.0: Affected
    • 3.3.1.0: Affected
    • 3.3.2.0: Affected
    • 3.3.3.0: Affected
    • 3.3.4.0: Affected
    • 3.3.5.0: Affected
    • 3.3.7.0: Affected
    • 3.5.0.0: Affected
    • 3.5.1.0: Affected
    • 3.8.1.0: Affected
    • 3.6.0.0: Affected
    • 3.6.2.0: Affected
    • 3.9.3.0: Affected
    • 3.7.2.0: Affected
    • 3.7.0.0: Affected
    • 3.9.6.0: Affected
    • 3.10.0.0: Affected
    • 3.10.2.0: Affected
    • 3.7.4.0: Affected
    • 3.9.0.0: Affected
    • 3.5.2.0: Affected
    • 3.12.1.0: Affected
    • 3.6.1.0: Affected
    • 3.9.2.0: Affected
    • 3.6.3.0: Affected

    No fix published

  • cisco secure firewall threat defense (ftd) software

    Versions
    • 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: Affected
    • 7.0.2.1: Affected
    • 7.0.3: Affected
    • 7.2.0.1: Affected
    • 7.0.4: Affected
    • 7.2.1: Affected
    • 7.0.5: Affected
    • 7.3.0: Affected
    • 7.2.2: Affected
    • 7.2.3: Affected
    • 7.3.1: Affected
    • 7.2.4: Affected
    • 7.0.6: Affected
    • 7.2.5: Affected
    • 7.2.4.1: Affected
    • 7.3.1.1: Affected
    • 7.4.0: Affected
    • 7.0.6.1: Affected
    • 7.2.5.1: Affected
    • 7.4.1: Affected
    • 7.2.6: Affected
    • 7.0.6.2: Affected
    • 7.4.1.1: Affected
    • 7.2.7: Affected
    • 7.2.5.2: Affected
    • 7.3.1.2: Affected
    • 7.2.8: Affected
    • 7.6.0: Affected
    • 7.4.2: Affected
    • 7.2.8.1: Affected
    • 7.0.6.3: Affected
    • 7.4.2.1: Affected
    • 7.2.9: Affected
    • 7.0.7: Affected
    • 7.7.0: Affected
    • 7.4.2.2: Affected
    • 7.2.10: Affected
    • 7.6.1: Affected
    • 7.4.2.3: Affected
    • 7.0.8: Affected
    • 7.6.2: Affected
    • 7.7.10: Affected
    • 7.7.11: Affected
    • 7.0.8.1: Affected
    • 7.6.2.1: Affected
    • 7.7.10.1: Affected
    • 7.4.2.4: Affected
    • 7.2.10.2: Affected
    • 7.4.3: Affected
    • 7.6.4: Affected
    • 10.0.0: Affected
    • 7.4.4: Affected
    • 7.0.9: Affected
    • 7.2.11: Affected
    • 7.4.7: Affected

    No fix published

  • cisco utd snort ips engine software

    Versions
    • 17.12.1a: Affected
    • 17.12.2: Affected
    • 17.13.1a: Affected
    • 17.12.3: Affected
    • 17.14.1a: Affected
    • 17.12.4: Affected
    • 17.12.3a: Affected
    • 17.15.1a: Affected
    • 17.16.1a: Affected
    • 17.12.4a: Affected
    • 17.15.2c: Affected
    • 17.12.4b: Affected
    • 17.15.2a: Affected
    • 17.12.5: Affected
    • 17.17.1: Affected
    • 17.12.5a: Affected
    • 17.15.3a: Affected
    • 17.15.3: Affected
    • 17.12.5b: Affected
    • 17.12.5c: Affected
    • 17.15.4: Affected
    • 17.18.1: Affected
    • 17.18.1a: Affected
    • 17.12.6: Affected
    • 17.15.4c: Affected
    • 17.12.5d: Affected
    • 17.18.2: Affected
    • 26.1.1: Affected
    • 17.15.5: Affected
    • 17.15.5a: Affected
    • 17.12.7: Affected
    • 17.12.7a: Affected
    • 17.12.7b: Affected
    • 17.18.3a: Affected
    • 17.12.8: Affected
    • 17.15.6: Affected
    • 17.18.4: Affected
    • 26.1.2: Affected

    No fix published

Original sources

Check your server →