Vulnerability in Cisco Secure Firewall Threat Defense (Ftd) Software
CVE-2026-20065
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.
EPSS: 0.004 (29.6th percentile) — read the EPSS interpretation.
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.
Affected products
- Cisco Secure Firewall Threat Defense (Ftd) Software — versions 7.0.0, 7.0.0.1, 7.0.1
- Cisco Utd Snort Ips Engine Software — versions 17.3.1a, 17.2.1r, 17.3.2
- Cisco Secure_firewall_threat_defense — versions 7.0.0, 7.0.0.1, 7.0.1
- Cisco Snort
- Cisco Unified_threat_defense_snort_intrusion_prevention_system_engine — versions 17.10.1a, 17.11.1a, 17.12.1a
Weakness classification (CWE)
References
- psirt@cisco.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-20065?
- CVE-2026-20065 is a medium-severity vulnerability in Cisco Secure Firewall Threat Defense (Ftd) Software, classified under Improper Locking. CVSS score: 5.8/10. Published 2026-03-04.
- How severe is CVE-2026-20065?
- Medium severity. CVSS v3 base score is 5.8 out of 10.