CVE-2026-20006
Last modified
CVE-2026-20006 is a medium-severity vulnerability rated 5.8/10 on the CVSS scale. A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpectedly restart, resulting in a denial of service (DoS) condition. This vulnerability is due to improper implementation of the TLS protocol. An attacker could exploit this vulnerability by sending a crafted TLS packet to an affected system. EPSS estimates a 0.37% chance of exploitation in the next 30 days.
Description
A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpectedly restart, resulting in a denial of service (DoS) condition. This vulnerability is due to improper implementation of the TLS protocol. An attacker could exploit this vulnerability by sending a crafted TLS packet to an affected system. A successful exploit could allow the attacker to cause a device that is running Cisco Secure FTD Software to drop network traffic, resulting in a DoS condition. Note: TLS 1.3 is not affected by this vulnerability.
Metrics
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| 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 | Secure Firewall Threat Defense | 7.6.1 |
| Cisco | Secure Firewall Threat Defense | 7.6.2 |
| Cisco | Secure Firewall Threat Defense | 7.6.2.1 |
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tcp-dos-rHfqnwRgVendor Advisory, Mitigation
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
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How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
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