Vulnerability in Cisco Secure Firewall Threat Defense (Ftd) Software
CVE-2026-20006
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.004 (28.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 7.2.0, 7.2.0.1, 7.2.1
- Cisco Secure Firewall Threat Defense — versions 7.2.0, 7.2.0.1, 7.2.1
Weakness classification (CWE)
References
- sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-… (Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20006?
- CVE-2026-20006 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense (Ftd) Software, classified under CWE-388. CVSS score: 5.8/10. Published 2026-03-04.
- How severe is CVE-2026-20006?
- Medium severity. CVSS v3 base score is 5.8 out of 10.