Vulnerability Intelligence Report
Multiple Cisco Products Snort 3 Software Hardening Release: October 2026
CVE-2026-20356
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.
No Active Exploit Signals
CVSS Base Score
7.5
HIGH
Exploitability:3.9
Impact Score:3.6
EPSS Probability:0.35%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
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SSVC Action
—
Weaknesses (CWE)
CWE-400 ↗Uncontrolled Resource Consumption
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Cisco | Cisco Cyber Vision | 3.0.0 (affected), 3.0.2 (affected), 3.0.3 (affected), 3.0.1 (affected), 3.1.0 (affected), 3.0.4 (affected), 3.1.1 (affected), 3.1.2 (affected), 3.2.0 (affected), 3.0.5 (affected), 3.2.1 (affected), 3.0.6 (affected), 3.2.2 (affected), 3.2.3 (affected), 3.2.4 (affected), 4.0.0 (affected), 4.0.1 (affected), 4.0.2 (affected), 4.0.3 (affected), 4.1.0 (affected), 4.1.1 (affected), 4.1.2 (affected), 4.1.3 (affected), 4.1.4 (affected), 4.2.0 (affected), 4.2.1 (affected), 4.1.5 (affected), 4.2.2 (affected), 4.2.X (affected), 4.2.3 (affected), 4.2.4 (affected), 4.2.6 (affected), 4.1.6 (affected), 4.3.0 (affected), 4.3.1 (affected), 4.3.2 (affected), 4.3.3 (affected), 4.4.0 (affected), 4.4.1 (affected), 4.4.2 (affected), 4.4.3 (affected), 4.1.7 (affected), 5.0.0 (affected), 5.0.1 (affected), 5.0.2 (affected), 5.1.0 (affected), 5.1.1 (affected), 5.1.2 (affected), 5.1.3 (affected), 5.2.0 (affected), 5.2.1 (affected), 5.3.0 (affected), 5.3.1 (affected), 5.3.2 (affected), 5.3.3 (affected), 5.5.1 (affected), 5.6.1 (affected), 5.4.0 (affected), 5.4.1 (affected), 5.4.2 (affected), 5.7.0 (affected), 5.8.1 (affected), 5.7.1 (affected), 5.8.0 (affected), 5.5.2 (affected) |
| Cisco | Cisco Open Source Snort3 | 3.12.2.0 (affected), 3.1.2.0 (affected), 3.1.3.0 (affected), 3.1.4.0 (affected), 3.1.5.0 (affected), 3.1.6.0 (affected), 3.1.7.0 (affected), 3.1.8.0 (affected), 3.1.9.0 (affected), 3.1.10.0 (affected), 3.1.12.0 (affected), 3.1.13.0 (affected), 3.1.14.0 (affected), 3.1.15.0 (affected), 3.1.16.0 (affected), 3.1.17.0 (affected), 3.1.18.0 (affected), 3.1.19.0 (affected), 3.1.20.0 (affected), 3.1.21.0 (affected), 3.1.22.0 (affected), 3.1.23.0 (affected), 3.1.24.0 (affected), 3.1.25.0 (affected), 3.1.27.0 (affected), 3.1.28.0 (affected), 3.1.29.0 (affected), 3.1.30.0 (affected), 3.1.31.0 (affected), 3.1.32.0 (affected), 3.1.36.0 (affected), 3.1.38.0 (affected), 3.1.39.0 (affected), 3.1.40.0 (affected), 3.1.41.0 (affected), 3.1.42.0 (affected), 3.1.43.0 (affected), 3.1.45.0 (affected), 3.1.47.0 (affected), 3.1.48.0 (affected), 3.1.50.0 (affected), 3.1.51.0 (affected), 3.1.52.0 (affected), 3.1.53.0 (affected), 3.1.55.0 (affected), 3.1.56.0 (affected), 3.1.57.0 (affected), 3.1.58.0 (affected), 3.1.59.0 (affected), 3.1.60.0 (affected), 3.1.61.0 (affected), 3.1.62.0 (affected), 3.1.63.0 (affected), 3.1.64.0 (affected), 3.1.65.0 (affected), 3.1.66.0 (affected), 3.1.67.0 (affected), 3.1.69.0 (affected), 3.1.70.0 (affected), 3.1.71.0 (affected), 3.1.72.0 (affected), 3.1.73.0 (affected), 3.1.74.0 (affected), 3.1.75.0 (affected), 3.1.76.0 (affected), 3.1.77.0 (affected), 3.1.78.0 (affected), 3.1.81.0 (affected), 3.1.82.0 (affected), 3.1.83.0 (affected), 3.1.84.0 (affected), 3.2.1.0 (affected), 3.2.2.0 (affected), 3.3.0.0 (affected), 3.3.1.0 (affected), 3.3.2.0 (affected), 3.3.3.0 (affected), 3.3.4.0 (affected), 3.3.5.0 (affected), 3.3.7.0 (affected), 3.5.0.0 (affected), 3.5.1.0 (affected), 3.8.1.0 (affected), 3.6.0.0 (affected), 3.6.2.0 (affected), 3.9.3.0 (affected), 3.7.2.0 (affected), 3.7.0.0 (affected), 3.9.6.0 (affected), 3.10.0.0 (affected), 3.10.2.0 (affected), 3.7.4.0 (affected), 3.9.0.0 (affected), 3.5.2.0 (affected), 3.12.1.0 (affected), 3.6.1.0 (affected), 3.9.2.0 (affected), 3.6.3.0 (affected), 3.9.5.0 (affected), 3.7.1.0 (affected), 3.9.7.0 (affected), 3.7.3.0 (affected), 3.10.1.0 (affected), 3.9.1.0 (affected), 3.11.1.0 (affected) |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.0.0 (affected), 7.0.0.1 (affected), 7.0.1 (affected), 7.0.1.1 (affected), 7.0.2 (affected), 7.2.0 (affected), 7.0.2.1 (affected), 7.0.3 (affected), 7.2.0.1 (affected), 7.0.4 (affected), 7.2.1 (affected), 7.0.5 (affected), 7.3.0 (affected), 7.2.2 (affected), 7.2.3 (affected), 7.3.1 (affected), 7.2.4 (affected), 7.0.6 (affected), 7.2.5 (affected), 7.2.4.1 (affected), 7.3.1.1 (affected), 7.4.0 (affected), 7.0.6.1 (affected), 7.2.5.1 (affected), 7.4.1 (affected), 7.2.6 (affected), 7.0.6.2 (affected), 7.4.1.1 (affected), 7.2.7 (affected), 7.2.5.2 (affected), 7.3.1.2 (affected), 7.2.8 (affected), 7.6.0 (affected), 7.4.2 (affected), 7.2.8.1 (affected), 7.0.6.3 (affected), 7.4.2.1 (affected), 7.2.9 (affected), 7.0.7 (affected), 7.7.0 (affected), 7.4.2.2 (affected), 7.2.10 (affected), 7.6.1 (affected), 7.4.2.3 (affected), 7.0.8 (affected), 7.6.2 (affected), 7.7.10 (affected), 7.7.11 (affected), 7.0.8.1 (affected), 7.6.2.1 (affected), 7.7.10.1 (affected), 7.4.2.4 (affected), 7.2.10.2 (affected), 7.4.3 (affected), 7.6.4 (affected), 10.0.0 (affected), 7.4.4 (affected), 7.0.9 (affected), 7.2.11 (affected), 7.4.7 (affected) |
| Cisco | Cisco UTD SNORT IPS Engine Software | 17.12.1a (affected), 17.12.2 (affected), 17.13.1a (affected), 17.12.3 (affected), 17.14.1a (affected), 17.12.4 (affected), 17.12.3a (affected), 17.15.1a (affected), 17.16.1a (affected), 17.12.4a (affected), 17.15.2c (affected), 17.12.4b (affected), 17.15.2a (affected), 17.12.5 (affected), 17.17.1 (affected), 17.12.5a (affected), 17.15.3a (affected), 17.15.3 (affected), 17.12.5b (affected), 17.12.5c (affected), 17.15.4 (affected), 17.18.1 (affected), 17.18.1a (affected), 17.12.6 (affected), 17.15.4c (affected), 17.12.5d (affected), 17.18.2 (affected), 26.1.1 (affected), 17.15.5 (affected), 17.15.5a (affected), 17.12.7 (affected), 17.12.7a (affected), 17.12.7b (affected), 17.18.3a (affected), 17.12.8 (affected), 17.15.6 (affected), 17.18.4 (affected), 26.1.2 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
EPSS Score
0.346%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Cisco Systems, Inc. · Hosted Service · USA |
| Reserved | 2025-10-08T11:59:15 |
| Published | 2026-10-21T16:13:06 |
| Last Updated | 2026-10-22T19:10:52 |
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