Denial of Service Vulnerability in Cisco Snort 3 Detection Engine
CVE-2026-20197

5.8MEDIUM

Key Information:

Vendor

Cisco
Status
Cisco Open Source Snort3
Cisco Secure Firewall Threat Defense (ftd) Software
Cisco Utd Snort Ips Engine Software
Vendor
CVE Published:
21 October 2026

Badges

👾 Exploit Exists

What is CVE-2026-20197?

A vulnerability exists in the Snort 3 Teredo Detection Engine of Cisco products that allows an unauthenticated remote attacker to trigger an unexpected restart of the detection engine, leading to a potential denial of service condition. This issue arises from insufficient error checking during the parsing of Teredo packets, allowing attackers to disrupt packet inspection by sending specially crafted packets to the targeted device. As a result, affected systems may experience service interruptions, compromising network security.

Affected Version(s)

Cisco Open Source Snort3 3.12.2.0

Cisco Open Source Snort3 3.1.2.0

Cisco Open Source Snort3 3.1.3.0

References

https://sec.cloudapps.cisco.com/security/center/content/C...

CVSS V3.1

Score:
5.8
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

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