Remote Code Execution Vulnerability in Cisco Snort 3 GRE Detection
CVE-2026-20179

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-2026-20179?

Multiple Cisco products have a vulnerability in the Snort 3 Generic Routing Encapsulation (GRE) Detection Engine. This flaw allows an unauthenticated, remote attacker to exploit the engine by sending crafted GRE packets, which can lead to unexpected restarts of the Snort 3 Detection Engine. The resulting denial of service can interrupt packet inspection, compromising the integrity of network security measures. This vulnerability is a result of insufficient error checking in the GRE packet parsing process.

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

.