Riskcovery

CVE-2026-20197

Multiple Cisco Products Snort 3 Teredo Protocol Denial of Service Vulnerability

State
Published
Severity
5.8 Medium
Published
Oct 21, 2026
Updated
Oct 22, 2026
Reserved
Oct 8, 2025

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.15.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Lcisco

Weaknesses

  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

Affected Products

ProductVersions
Cisco Open Source Snort3Cisco
  • 3.12.2.0Affected
  • 3.1.2.0Affected
  • 3.1.3.0Affected
  • 3.1.4.0Affected
  • 3.1.5.0Affected
  • 3.1.6.0Affected
  • 3.1.7.0Affected
  • 3.1.8.0Affected
  • 3.1.9.0Affected
  • 3.1.10.0Affected
  • 3.1.12.0Affected
  • 3.1.13.0Affected
  • 3.1.14.0Affected
  • 3.1.15.0Affected
  • 3.1.16.0Affected
  • 3.1.17.0Affected
  • 3.1.18.0Affected
  • 3.1.19.0Affected
  • 3.1.20.0Affected
  • 3.1.21.0Affected
  • 3.1.22.0Affected
  • 3.1.23.0Affected
  • 3.1.24.0Affected
  • 3.1.25.0Affected
  • 3.1.27.0Affected
  • and 80 more versions
Cisco Secure Firewall Threat Defense (FTD) SoftwareCisco
  • 7.0.0Affected
  • 7.0.0.1Affected
  • 7.0.1Affected
  • 7.0.1.1Affected
  • 7.0.2Affected
  • 7.2.0Affected
  • 7.0.2.1Affected
  • 7.0.3Affected
  • 7.2.0.1Affected
  • 7.0.4Affected
  • 7.2.1Affected
  • 7.0.5Affected
  • 7.3.0Affected
  • 7.2.2Affected
  • 7.2.3Affected
  • 7.3.1Affected
  • 7.2.4Affected
  • 7.0.6Affected
  • 7.2.5Affected
  • 7.2.4.1Affected
  • 7.3.1.1Affected
  • 7.4.0Affected
  • 7.0.6.1Affected
  • 7.2.5.1Affected
  • 7.4.1Affected
  • and 35 more versions
Cisco UTD SNORT IPS Engine SoftwareCisco
  • 17.12.1aAffected
  • 17.12.2Affected
  • 17.13.1aAffected
  • 17.12.3Affected
  • 17.14.1aAffected
  • 17.12.4Affected
  • 17.12.3aAffected
  • 17.15.1aAffected
  • 17.16.1aAffected
  • 17.12.4aAffected
  • 17.15.2cAffected
  • 17.12.4bAffected
  • 17.15.2aAffected
  • 17.12.5Affected
  • 17.17.1Affected
  • 17.12.5aAffected
  • 17.15.3aAffected
  • 17.15.3Affected
  • 17.12.5bAffected
  • 17.12.5cAffected
  • 17.15.4Affected
  • 17.18.1Affected
  • 17.18.1aAffected
  • 17.12.6Affected
  • 17.15.4cAffected
  • and 13 more versions

References

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