cisco-sa-hardening-snort3-ybgmhTQeCriticalCVSS 9.0

Multiple Cisco Products Snort 3 Security Hardening Release: October 2026

Published
October 21, 2026
Last Modified
October 22, 2026

🔗 CVE IDs covered (4)

CVE-2026-20043 →CVE-2026-20236 →CVE-2026-20291 →CVE-2026-20356 →

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

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco-owned Open Source Snort 3 engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.

These vulnerabilities were found during internal testing and are not known to be actively exploited. To assist customers in patching and to streamline the disclosure process, Cisco has grouped these issues by their underlying vulnerability class - Common Weakness Enumeration (CWE) - and assigned a single Common Vulnerabilities and Exposures Identifier (CVE ID) to each CWE grouping.

Note: Cisco may publish separate security advisories that provide additional details about individual vulnerabilities that are addressed in this release.

Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.

This advisory is part of a group of advisories. For a complete list of the advisories and links to them, see Cisco Advance Notification for Publication of October 21, 2026, Security Advisories ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-notice-QGwHnJ6k"].

CVE-2026-20043 — Multiple Cisco Products Snort 3 Software Hardening Release: October 2026 (CVSS 3.1 9.0, CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H) CVE-2026-20236 — Multiple Cisco Products Snort 3 Software Hardening Release: October 2026 (CVSS 3.1 7.5, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H) CVE-2026-20291 — Multiple Cisco Products Snort 3 Software Hardening Release: October 2026 (CVSS 3.1 7.8, CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) CVE-2026-20356 — Multiple Cisco Products Snort 3 Software Hardening Release: October 2026 (CVSS 3.1 7.5, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

🎯 Affected products270

  • Cisco Cyber Vision
  • Cisco Open Source Snort3
  • Cisco Secure Firewall Threat Defense (FTD) Software
  • Cisco UTD SNORT IPS Engine Software
  • Cisco Cyber Vision .0
  • Cisco Cyber Vision .1
  • Cisco Cyber Vision .2
  • Cisco Cyber Vision .3
  • Cisco Cyber Vision 3.0.0
  • Cisco Cyber Vision 3.0.1
  • Cisco Cyber Vision 3.0.2
  • Cisco Cyber Vision 3.0.3
  • Cisco Cyber Vision 3.0.4
  • Cisco Cyber Vision 3.0.5
  • Cisco Cyber Vision 3.0.6
  • Cisco Cyber Vision 3.1.0
  • Cisco Cyber Vision 3.1.1
  • Cisco Cyber Vision 3.1.2
  • Cisco Cyber Vision 3.2.0
  • Cisco Cyber Vision 3.2.1
  • Cisco Cyber Vision 3.2.2
  • Cisco Cyber Vision 3.2.3
  • Cisco Cyber Vision 3.2.4
  • Cisco Cyber Vision 4.0.0
  • Cisco Cyber Vision 4.0.1
  • Cisco Cyber Vision 4.0.2
  • Cisco Cyber Vision 4.0.3
  • Cisco Cyber Vision 4.1.0
  • Cisco Cyber Vision 4.1.1
  • Cisco Cyber Vision 4.1.2
  • +240 more not shown

✅ Remediation

Cisco has released software updates that address this vulnerability. https://software.cisco.com Workarounds: There are no workarounds that address these vulnerabilities.

🔗 References (4)