CVE-2026-20005: Multiple Cisco Products Snort 3 SSL 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 incomplete parsing of the SSL handshake ingress packets. An attacker could exploit this vulnerability by sending crafted SSL handshake packets. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine restarts unexpectedly.
Affected Software
110 affected components
Cisco Snort 3 Detection Engine
Cisco Cyber Vision=3.0.0
Cisco Cyber Vision=3.0.1
Cisco Cyber Vision=3.0.2
Cisco Cyber Vision=3.0.3
Cisco Cyber Vision=3.0.4
Cisco Cyber Vision=3.0.5
Cisco Cyber Vision=3.0.6
Cisco Cyber Vision=3.1.0
Cisco Cyber Vision=3.1.1
Cisco Cyber Vision=3.1.2
Cisco Cyber Vision=3.2.0
Cisco Cyber Vision=3.2.1
Cisco Cyber Vision=3.2.2
Cisco Cyber Vision=3.2.3
Cisco Cyber Vision=3.2.4
Cisco Cyber Vision=4.0.0
Cisco Cyber Vision=4.0.1
Cisco Cyber Vision=4.0.2
Cisco Cyber Vision=4.0.3
Cisco Cyber Vision=4.1.0
Cisco Cyber Vision=4.1.1
Cisco Cyber Vision=4.1.2
Cisco Cyber Vision=4.1.3
Cisco Cyber Vision=4.1.4
Cisco Cyber Vision=4.1.5
Cisco Cyber Vision=4.1.6
Cisco Cyber Vision=4.1.7
Cisco Cyber Vision=4.2.0
Cisco Cyber Vision=4.2.1
Cisco Cyber Vision=4.2.2
Cisco Cyber Vision=4.2.3
Cisco Cyber Vision=4.2.4
Cisco Cyber Vision=4.2.6
Cisco Cyber Vision=4.3.0
Cisco Cyber Vision=4.3.1
Cisco Cyber Vision=4.3.2
Cisco Cyber Vision=4.3.3
Cisco Cyber Vision=4.4.0
Cisco Cyber Vision=4.4.1
Cisco Cyber Vision=4.4.2
Cisco Cyber Vision=4.4.3
Cisco Cyber Vision=5.0.0
Cisco Cyber Vision=5.0.1
Cisco Cyber Vision=5.0.2
Cisco Cyber Vision=5.1.0
Cisco Cyber Vision=5.1.1
Cisco Cyber Vision=5.1.2
Cisco Cyber Vision=5.1.3
Cisco Cyber Vision=5.2.0
Cisco Cyber Vision=5.2.1
Cisco Cyber Vision=5.3.0
Cisco Cyber Vision=5.3.1
Cisco Cyber Vision=5.3.2
Cisco Secure Firewall Threat Defense=7.6.0
Cisco Secure Firewall Threat Defense=7.6.1
Cisco Secure Firewall Threat Defense=7.6.2
Cisco Secure Firewall Threat Defense=7.6.2.1
Cisco Secure Firewall Threat Defense=7.7.0
Cisco Secure Firewall Threat Defense=7.7.10
Cisco Secure Firewall Threat Defense=7.7.10.1
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.4
Cisco Unified Threat Defense Snort Intrusion Prevention System Engine=17.9.5e
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
All of the following
Cisco Snort>=3.0.0-233<3.9.2.0
Any of the following
Cisco Meraki Mx100
Cisco Meraki Mx105
Cisco Meraki Mx250
Cisco Meraki Mx400
Cisco Meraki Mx450
Cisco Meraki Mx600
Cisco Meraki Mx64
Cisco Meraki Mx64w
Cisco Meraki Mx65
Cisco Meraki Mx65w
Cisco Meraki Mx67
Cisco Meraki Mx67c
Cisco Meraki Mx67w
Cisco Meraki Mx68
Cisco Meraki Mx68cw
Cisco Meraki Mx75
Cisco Meraki Mx84
Cisco Meraki Mx85
Cisco Meraki Mx95
Event History
Mar 4, 2026
CVE Published
via MITRE·05:02 PM
Data Sourced
via MITRE·05:02 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:16 PM
DescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-20005?
CVE-2026-20005 has been classified with a moderate severity rating due to its potential impact on system availability.
2
How do I fix CVE-2026-20005?
To mitigate CVE-2026-20005, it is recommended to update the Cisco Snort 3 Detection Engine to the latest version that addresses this vulnerability.
3
What are the effects of CVE-2026-20005 on affected systems?
CVE-2026-20005 can cause the Snort 3 Detection Engine to restart, leading to denial of service for network traffic analysis.
4
Who is impacted by CVE-2026-20005?
Organizations using the Cisco Snort 3 Detection Engine are affected by CVE-2026-20005.
5
Is authentication required to exploit CVE-2026-20005?
No, CVE-2026-20005 can be exploited by unauthenticated remote attackers.