CVE-2026-20043 PUBLISHED

Multiple Cisco Products Snort 3 Software Hardening Release: October 2026

Assigner: cisco
Reserved: 08.10.2025 Published: 21.10.2026 Updated: 22.10.2026

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-2026-20043 are related to issues concerning out-of-bounds writes that are grouped under the Common Weakness Enumeration (CWE) Base CWE-787.

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CVSS Score: 9

Attack Vector	Network	Scope	Changed
Attack Complexity	High	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	Cisco
Product	Cisco Cyber Vision
Versions	Default: unknown Version 3.0.0 is affected Version 3.0.2 is affected Version 3.0.3 is affected Version 3.0.1 is affected Version 3.1.0 is affected Version 3.0.4 is affected Version 3.1.1 is affected Version 3.1.2 is affected Version 3.2.0 is affected Version 3.0.5 is affected Version 3.2.1 is affected Version 3.0.6 is affected Version 3.2.2 is affected Version 3.2.3 is affected Version 3.2.4 is affected Version 4.0.0 is affected Version 4.0.1 is affected Version 4.0.2 is affected Version 4.0.3 is affected Version 4.1.0 is affected Version 4.1.1 is affected Version 4.1.2 is affected Version 4.1.3 is affected Version 4.1.4 is affected Version 4.2.0 is affected Version 4.2.1 is affected Version 4.1.5 is affected Version 4.2.2 is affected Version 4.2.X is affected Version 4.2.3 is affected Version 4.2.4 is affected Version 4.2.6 is affected Version 4.1.6 is affected Version 4.3.0 is affected Version 4.3.1 is affected Version 4.3.2 is affected Version 4.3.3 is affected Version 4.4.0 is affected Version 4.4.1 is affected Version 4.4.2 is affected Version 4.4.3 is affected Version 4.1.7 is affected Version 5.0.0 is affected Version 5.0.1 is affected Version 5.0.2 is affected Version 5.1.0 is affected Version 5.1.1 is affected Version 5.1.2 is affected Version 5.1.3 is affected Version 5.2.0 is affected Version 5.2.1 is affected Version 5.3.0 is affected Version 5.3.1 is affected Version 5.3.2 is affected Version 5.3.3 is affected Version 5.5.1 is affected Version 5.6.1 is affected Version 5.4.0 is affected Version 5.4.1 is affected Version 5.4.2 is affected Version 5.7.0 is affected Version 5.8.1 is affected Version 5.7.1 is affected Version 5.8.0 is affected Version 5.5.2 is affected

Vendor	Cisco
Product	Cisco Open Source Snort3
Versions	Default: unknown Version 3.12.2.0 is affected Version 3.1.2.0 is affected Version 3.1.3.0 is affected Version 3.1.4.0 is affected Version 3.1.5.0 is affected Version 3.1.6.0 is affected Version 3.1.7.0 is affected Version 3.1.8.0 is affected Version 3.1.9.0 is affected Version 3.1.10.0 is affected Version 3.1.12.0 is affected Version 3.1.13.0 is affected Version 3.1.14.0 is affected Version 3.1.15.0 is affected Version 3.1.16.0 is affected Version 3.1.17.0 is affected Version 3.1.18.0 is affected Version 3.1.19.0 is affected Version 3.1.20.0 is affected Version 3.1.21.0 is affected Version 3.1.22.0 is affected Version 3.1.23.0 is affected Version 3.1.24.0 is affected Version 3.1.25.0 is affected Version 3.1.27.0 is affected Version 3.1.28.0 is affected Version 3.1.29.0 is affected Version 3.1.30.0 is affected Version 3.1.31.0 is affected Version 3.1.32.0 is affected Version 3.1.36.0 is affected Version 3.1.38.0 is affected Version 3.1.39.0 is affected Version 3.1.40.0 is affected Version 3.1.41.0 is affected Version 3.1.42.0 is affected Version 3.1.43.0 is affected Version 3.1.45.0 is affected Version 3.1.47.0 is affected Version 3.1.48.0 is affected Version 3.1.50.0 is affected Version 3.1.51.0 is affected Version 3.1.52.0 is affected Version 3.1.53.0 is affected Version 3.1.55.0 is affected Version 3.1.56.0 is affected Version 3.1.57.0 is affected Version 3.1.58.0 is affected Version 3.1.59.0 is affected Version 3.1.60.0 is affected Version 3.1.61.0 is affected Version 3.1.62.0 is affected Version 3.1.63.0 is affected Version 3.1.64.0 is affected Version 3.1.65.0 is affected Version 3.1.66.0 is affected Version 3.1.67.0 is affected Version 3.1.69.0 is affected Version 3.1.70.0 is affected Version 3.1.71.0 is affected Version 3.1.72.0 is affected Version 3.1.73.0 is affected Version 3.1.74.0 is affected Version 3.1.75.0 is affected Version 3.1.76.0 is affected Version 3.1.77.0 is affected Version 3.1.78.0 is affected Version 3.1.81.0 is affected Version 3.1.82.0 is affected Version 3.1.83.0 is affected Version 3.1.84.0 is affected Version 3.2.1.0 is affected Version 3.2.2.0 is affected Version 3.3.0.0 is affected Version 3.3.1.0 is affected Version 3.3.2.0 is affected Version 3.3.3.0 is affected Version 3.3.4.0 is affected Version 3.3.5.0 is affected Version 3.3.7.0 is affected Version 3.5.0.0 is affected Version 3.5.1.0 is affected Version 3.8.1.0 is affected Version 3.6.0.0 is affected Version 3.6.2.0 is affected Version 3.9.3.0 is affected Version 3.7.2.0 is affected Version 3.7.0.0 is affected Version 3.9.6.0 is affected Version 3.10.0.0 is affected Version 3.10.2.0 is affected Version 3.7.4.0 is affected Version 3.9.0.0 is affected Version 3.5.2.0 is affected Version 3.12.1.0 is affected Version 3.6.1.0 is affected Version 3.9.2.0 is affected Version 3.6.3.0 is affected Version 3.9.5.0 is affected Version 3.7.1.0 is affected Version 3.9.7.0 is affected Version 3.7.3.0 is affected Version 3.10.1.0 is affected Version 3.9.1.0 is affected Version 3.11.1.0 is affected

Vendor	Cisco
Product	Cisco Secure Firewall Threat Defense (FTD) Software
Versions	Default: unknown Version 7.0.0 is affected Version 7.0.0.1 is affected Version 7.0.1 is affected Version 7.0.1.1 is affected Version 7.0.2 is affected Version 7.0.2.1 is affected Version 7.0.3 is affected Version 7.2.0.1 is affected Version 7.0.4 is affected Version 7.2.1 is affected Version 7.0.5 is affected Version 7.3.0 is affected Version 7.2.2 is affected Version 7.2.3 is affected Version 7.3.1 is affected Version 7.2.4 is affected Version 7.0.6 is affected Version 7.2.5 is affected Version 7.2.4.1 is affected Version 7.3.1.1 is affected Version 7.4.0 is affected Version 7.0.6.1 is affected Version 7.2.5.1 is affected Version 7.4.1 is affected Version 7.2.6 is affected Version 7.0.6.2 is affected Version 7.4.1.1 is affected Version 7.2.7 is affected Version 7.2.5.2 is affected Version 7.3.1.2 is affected Version 7.2.8 is affected Version 7.6.0 is affected Version 7.4.2 is affected Version 7.2.8.1 is affected Version 7.0.6.3 is affected Version 7.4.2.1 is affected Version 7.2.9 is affected Version 7.0.7 is affected Version 7.7.0 is affected Version 7.4.2.2 is affected Version 7.2.10 is affected Version 7.6.1 is affected Version 7.4.2.3 is affected Version 7.0.8 is affected Version 7.6.2 is affected Version 7.7.10 is affected Version 7.7.11 is affected Version 7.0.8.1 is affected Version 7.6.2.1 is affected Version 7.7.10.1 is affected Version 7.4.2.4 is affected Version 7.2.10.2 is affected Version 7.4.3 is affected Version 7.6.4 is affected Version 10.0.0 is affected Version 7.4.4 is affected Version 7.0.9 is affected Version 7.2.11 is affected Version 7.4.7 is affected

Vendor	Cisco
Product	Cisco UTD SNORT IPS Engine Software
Versions	Default: unknown Version 17.3.1a is affected Version 17.3.2 is affected Version 17.4.1a is affected Version 17.5.1 is affected Version 17.3.3 is affected Version 17.5.1a is affected Version 17.3.4 is affected Version 17.3.4a is affected Version 17.4.2 is affected Version 17.4.1b is affected Version 17.6.1a is affected Version 17.7.1a is affected Version 17.6.2 is affected Version 17.8.1a is affected Version 17.3.5 is affected Version 17.6.3 is affected Version 17.6.3a is affected Version 17.7.2 is affected Version 17.9.1a is affected Version 17.6.4 is affected Version 17.10.1a is affected Version 17.3.6 is affected Version 17.3.7 is affected Version 17.9.2a is affected Version 17.6.5 is affected Version 17.11.1a is affected Version 17.9.3a is affected Version 17.12.1a is affected Version 17.9.4 is affected Version 17.6.6 is affected Version 17.3.8 is affected Version 17.3.8a is affected Version 17.6.6a is affected Version 17.9.4a is affected Version 17.12.2 is affected Version 17.13.1a is affected Version 17.9.5a is affected Version 17.12.3 is affected Version 17.6.7 is affected Version 17.14.1a is affected Version 17.12.4 is affected Version 17.12.3a is affected Version 17.15.1a is affected Version 17.6.8 is affected Version 17.9.6 is affected Version 17.6.8a is affected Version 17.16.1a is affected Version 17.9.5e is affected Version 17.12.4a is affected Version 17.15.2c is affected Version 17.9.5f is affected Version 17.12.4b is affected Version 17.15.2a is affected Version 17.12.5 is affected Version 17.17.1 is affected Version 17.12.5a is affected Version 17.9.7a is affected Version 17.15.3a is affected Version 17.15.3 is affected Version 17.12.5b is affected Version 17.12.5c is affected Version 17.15.4 is affected Version 17.9.7b is affected Version 17.18.1 is affected Version 17.18.1a is affected Version 17.12.6 is affected Version 17.9.8 is affected Version 17.15.4c is affected Version 17.12.5d is affected Version 17.18.2 is affected Version 26.1.1 is affected Version 17.15.5 is affected Version 17.15.5a is affected Version 17.12.7 is affected Version 17.12.7a is affected Version 17.12.7b is affected Version 17.9.9 is affected Version 17.18.3a is affected Version 17.12.8 is affected Version 17.15.6 is affected Version 17.18.4 is affected Version 26.1.2 is affected Version 17.9.10 is affected

Exploits

The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.

References

cisco-sa-hardening-snort3-ybgmhTQe

Problem Types

Out-of-bounds Write cwe