CVE-2026-20066
Multiple Cisco Products Snort 3 TBD Denial of Service Vulnerability
MEDIUM 5.8
At a glance
- Source
- NVD
- EPSS
- EPSS 0.48 % · percentile 41 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- cisco
- NVD status
- Analyzed
Description
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 JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP 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. JSTokenizer is not enabled by default.
Weaknesses (CWE)
- CWE-400 — Uncontrolled Resource Consumption (DoS)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L | cisco |
| CVSS 3.1 | MEDIUM 5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L | NVD · psirt@cisco.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-9465
- GCVE · GCVE-0-2026-20066
Affected configurations (NVD CPE)
cpe:2.3:a:cisco:snort:*:*:*:*:*:*:*:*≥ 3.0.0-233 < 3.9.7.0cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.0:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.1.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.2:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.2.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.2.2:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.2.3:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.2.4:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.4.3:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.6.0:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.6.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.6.2:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.6.2.1:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.7.0:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.7.10:*:*:*:*:*:*:*cpe:2.3:a:cisco:secure_firewall_threat_defense:7.7.10.1:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.2.1r:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.1a:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.2:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.3:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.4:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.4a:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.5:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.6:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.7:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.8:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.3.8a:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.4.1a:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.4.1b:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.4.2:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.5.1:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.5.1a:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.6.1a:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.6.2:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.6.3:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.6.3a:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.6.4:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.6.5:*:*:*:*:*:*:*cpe:2.3:o:cisco:unified_threat_defense_snort_intrusion_prevention_system_engine:17.6.6:*:*:*:*:*:*:*- +48 more
Affected products
| Product | Versions |
|---|---|
| Cisco · Cisco Secure Firewall Threat Defense (FTD) Software | affected 7.4.0 ; affected 7.4.1 ; affected 7.4.1.1 ; affected 7.6.0 ; affected 7.4.2 ; affected 7.4.2.1 |
| Cisco · Cisco UTD SNORT IPS Engine Software | affected 17.3.1a ; affected 17.2.1r ; affected 17.3.2 ; affected 17.4.1a ; affected 17.5.1 ; affected 17.3.3 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |