Medium 5.8Published Mar 4, 2026

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

Updated under an hour ago (Oct 27, 2026, 4:23 AM ET)

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It affects Cisco Secure Firewall Threat Defense (FTD) Software and 4 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Cisco Secure Firewall Threat Defense (FTD) Software

Exploited in the last 30 days

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.

CVSS: 5.8 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Weakness (CWE): CWE-667
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: cisco
NVD analysis: Analyzed
Record last updated: Mar 4, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Cisco Cisco Secure Firewall Threat Defense (FTD) Software cisco:secure_firewall_threat_defense_ftd_software (from the name)	7.0.0; 7.0.0.1; 7.0.1; 7.1.0; 7.0.1.1; 7.1.0.1; 7.0.2; 7.2.0; and 42 more ranges	CNA record
Cisco Cisco UTD SNORT IPS Engine Software cisco:utd_snort_ips_engine_software (from the name)	17.3.1a; 17.2.1r; 17.3.2; 17.4.1a; 17.5.1; 17.3.3; 17.5.1a; 17.3.4; and 63 more ranges	CNA record
cisco snort cisco:snort	from 3.0.0-233 before 3.6.3.0	NVD
cisco secure_firewall_threat_defense cisco:secure_firewall_threat_defense	7.0.0; 7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.0.2.1; 7.0.3; 7.0.4; and 42 more ranges	NVD
cisco unified_threat_defense_snort_intrusion_prevention_system_engine cisco:unified_threat_defense_snort_intrusion_prevention_system_engine	17.2.1r; 17.3.1a; 17.3.2; 17.3.3; 17.3.4; 17.3.4a; 17.3.5; 17.3.6; and 63 more ranges	NVD

References

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-multi-dos-XFWkWSwz	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.