CVE-2026-20356
Multiple Cisco Products Snort 3 Software Hardening Release: October 2026
Description
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco owned Open Source Snort 3 Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20356 are related to issues concerning uncontrolled resource consumption that are grouped under the Common Weakness Enumeration (CWE) Base CWE-400.
Weakness: CWE-400
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Cyber Vision | OT / IoT Security | cna-assigner |
| Cisco | Cisco Firepower Threat Defense (FTD) Check your version | Firewall / NGFW | cna-assigner |
| Cisco | Cisco UTD SNORT IPS Engine | Threat Detection & Sandbox | cna-assigner |
Vendor-reported products (4)
- Cisco · Cisco Cyber Vision
- Cisco · Cisco Open Source Snort3
- Cisco · Cisco Secure Firewall Threat Defense (FTD) Software
- Cisco · Cisco UTD SNORT IPS Engine Software
Vendor advisory
cisco-sa-hardening-snort3-ybgmhTQe
Multiple Cisco Products Snort 3 Security Hardening Release: October 2026
Cisco’s rating: Critical (advisory CVSS 9.0) · Published Oct 21, 2026
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from