CVE-2026-20065: Multiple Cisco Products Snort 3 TBD Denial of Service Vulnerability

Published Mar 4, 2026
·
Updated

Multiple Cisco products are affected by a vulnerability in the Snort 3 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 an error in the binder module initialization logic of the Snort Detection Engine. An attacker could exploit this vulnerability by sending certain packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly.

Affected Software

123 affected components
Cisco Snort 3
Cisco Snort>=3.0.0-233<3.6.3.0
Cisco Secure Firewall Threat Defense=7.0.0
Cisco Secure Firewall Threat Defense=7.0.0.1
Cisco Secure Firewall Threat Defense=7.0.1
Cisco Secure Firewall Threat Defense=7.0.1.1
Cisco Secure Firewall Threat Defense=7.0.2
Cisco Secure Firewall Threat Defense=7.0.2.1
Cisco Secure Firewall Threat Defense=7.0.3
Cisco Secure Firewall Threat Defense=7.0.4
Cisco Secure Firewall Threat Defense=7.0.5
Cisco Secure Firewall Threat Defense=7.0.6
Cisco Secure Firewall Threat Defense=7.0.6.1
Cisco Secure Firewall Threat Defense=7.0.6.2
Cisco Secure Firewall Threat Defense=7.0.6.3
Cisco Secure Firewall Threat Defense=7.0.7
Cisco Secure Firewall Threat Defense=7.0.8
Cisco Secure Firewall Threat Defense=7.0.8.1
Cisco Secure Firewall Threat Defense=7.1.0
Cisco Secure Firewall Threat Defense=7.1.0.1
Cisco Secure Firewall Threat Defense=7.1.0.2
Cisco Secure Firewall Threat Defense=7.1.0.3
Cisco Secure Firewall Threat Defense=7.2.0
Cisco Secure Firewall Threat Defense=7.2.0.1
Cisco Secure Firewall Threat Defense=7.2.1
Cisco Secure Firewall Threat Defense=7.2.2
Cisco Secure Firewall Threat Defense=7.2.3
Cisco Secure Firewall Threat Defense=7.2.4
Cisco Secure Firewall Threat Defense=7.2.4.1
Cisco Secure Firewall Threat Defense=7.2.5
Cisco Secure Firewall Threat Defense=7.2.5.1
Cisco Secure Firewall Threat Defense=7.2.5.2
Cisco Secure Firewall Threat Defense=7.2.6
Cisco Secure Firewall Threat Defense=7.2.7
Cisco Secure Firewall Threat Defense=7.2.8
Cisco Secure Firewall Threat Defense=7.2.8.1
Cisco Secure Firewall Threat Defense=7.2.9
Cisco Secure Firewall Threat Defense=7.2.10
Cisco Secure Firewall Threat Defense=7.2.10.2
Cisco Secure Firewall Threat Defense=7.3.0
Cisco Secure Firewall Threat Defense=7.3.1
Cisco Secure Firewall Threat Defense=7.3.1.1
Cisco Secure Firewall Threat Defense=7.3.1.2
Cisco Secure Firewall Threat Defense=7.4.0
Cisco Secure Firewall Threat Defense=7.4.1
Cisco Secure Firewall Threat Defense=7.4.1.1
Cisco Secure Firewall Threat Defense=7.4.2
Cisco Secure Firewall Threat Defense=7.4.2.1
Cisco Secure Firewall Threat Defense=7.4.2.2
Cisco Secure Firewall Threat Defense=7.4.2.3
Cisco Secure Firewall Threat Defense=7.4.2.4
Cisco Secure Firewall Threat Defense=7.6.0
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.2.1r
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.2
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.3
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.4
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.4a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.5
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.6
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.7
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.8
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.3.8a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.4.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.4.1b
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.4.2
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.5.1
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.5.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.2
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.3
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.3a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.4
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.5
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.6
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.6a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.7
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.8
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.6.8a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.7.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.7.2
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.8.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.2a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.3a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.4
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.4a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.5a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.5e
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.5f
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.6
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.7a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.7b
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.8
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.10.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.11.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.2
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.3
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.3a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.4
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.4a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.4b
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.5
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.5a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.5b
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.5c
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.5d
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.12.6
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.13.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.14.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.15.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.15.2a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.15.2c
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.15.3
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.15.3a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.15.4
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.15.4c
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.16.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.17.1
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.18.1
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.18.1a
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.18.2

Event History

Mar 4, 2026
CVE Published
via MITRE·05:48 PM
Data Sourced
via MITRE·05:48 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·06:16 PM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-20065?

CVE-2026-20065 is considered a denial of service vulnerability that can disrupt services in affected Cisco products.

2

How do I fix CVE-2026-20065?

To mitigate CVE-2026-20065, ensure you apply the latest patches provided by Cisco for the Snort 3 Detection Engine.

3

What products are affected by CVE-2026-20065?

CVE-2026-20065 specifically affects Cisco Snort 3 implementations.

4

Can CVE-2026-20065 be exploited by authenticated users?

No, CVE-2026-20065 can be exploited by unauthenticated, remote attackers.

5

What impact does CVE-2026-20065 have on network security?

The impact of CVE-2026-20065 is that it can lead to a denial of service, thereby interrupting normal packet inspection and network operations.

Company

Resources

Contact

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