--- id: CVE-2026-20053 title: "Multiple Cisco products are affected by a vulnerability in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash.\r\n\r\nThis vulnerability is due to improper range checki…" summary: "Multiple Cisco products are affected by a vulnerability in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash.\r\n\r\nThis vulnerability is due to improper range checki…" severity: medium cvss: 5.8 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L' cwe: - CWE-122 vendor: cisco product: snort affected: - 'snort >= 3.0.0-233, < 3.9.3.0' - cyber_vision = 3.0.0 - cyber_vision = 3.0.1 - cyber_vision = 3.0.2 - cyber_vision = 3.0.3 - cyber_vision = 3.0.4 - cyber_vision = 3.0.5 - cyber_vision = 3.0.6 - cyber_vision = 3.1.0 - cyber_vision = 3.1.1 - cyber_vision = 3.1.2 - cyber_vision = 3.2.0 - cyber_vision = 3.2.1 - cyber_vision = 3.2.2 - cyber_vision = 3.2.3 - cyber_vision = 3.2.4 - cyber_vision = 4.0.0 - cyber_vision = 4.0.1 - cyber_vision = 4.0.2 - cyber_vision = 4.0.3 - cyber_vision = 4.1.0 - cyber_vision = 4.1.1 - cyber_vision = 4.1.2 - cyber_vision = 4.1.3 - cyber_vision = 4.1.4 - cyber_vision = 4.1.5 - cyber_vision = 4.1.6 - cyber_vision = 4.1.7 - cyber_vision = 4.2.0 - cyber_vision = 4.2.1 - cyber_vision = 4.2.2 - cyber_vision = 4.2.3 - cyber_vision = 4.2.4 - cyber_vision = 4.2.6 - cyber_vision = 4.3.0 - cyber_vision = 4.3.1 - cyber_vision = 4.3.2 - cyber_vision = 4.3.3 - cyber_vision = 4.4.0 - cyber_vision = 4.4.1 - cyber_vision = 4.4.2 - cyber_vision = 4.4.3 - cyber_vision = 5.0.0 - cyber_vision = 5.0.1 - cyber_vision = 5.0.2 - cyber_vision = 5.1.0 - cyber_vision = 5.1.1 - cyber_vision = 5.1.2 - cyber_vision = 5.1.3 - cyber_vision = 5.2.0 - cyber_vision = 5.2.1 - cyber_vision = 5.3.0 - cyber_vision = 5.3.1 - cyber_vision = 5.3.2 - secure_firewall_threat_defense = 7.2.0 - secure_firewall_threat_defense = 7.2.0.1 - secure_firewall_threat_defense = 7.2.1 - secure_firewall_threat_defense = 7.2.2 - secure_firewall_threat_defense = 7.2.3 - secure_firewall_threat_defense = 7.2.4 - secure_firewall_threat_defense = 7.2.4.1 - secure_firewall_threat_defense = 7.2.5 - secure_firewall_threat_defense = 7.2.5.1 - secure_firewall_threat_defense = 7.2.5.2 - secure_firewall_threat_defense = 7.2.6 - secure_firewall_threat_defense = 7.2.7 - secure_firewall_threat_defense = 7.2.8 - secure_firewall_threat_defense = 7.2.8.1 - secure_firewall_threat_defense = 7.2.9 - secure_firewall_threat_defense = 7.2.10 - secure_firewall_threat_defense = 7.2.10.2 - secure_firewall_threat_defense = 7.3.0 - secure_firewall_threat_defense = 7.3.1 - secure_firewall_threat_defense = 7.3.1.1 - secure_firewall_threat_defense = 7.3.1.2 - secure_firewall_threat_defense = 7.4.0 - secure_firewall_threat_defense = 7.4.1 - secure_firewall_threat_defense = 7.4.1.1 - secure_firewall_threat_defense = 7.4.2 - secure_firewall_threat_defense = 7.4.2.1 - secure_firewall_threat_defense = 7.4.2.2 - secure_firewall_threat_defense = 7.4.2.3 - secure_firewall_threat_defense = 7.4.2.4 - secure_firewall_threat_defense = 7.4.3 - secure_firewall_threat_defense = 7.6.0 - secure_firewall_threat_defense = 7.6.1 - secure_firewall_threat_defense = 7.6.2 - secure_firewall_threat_defense = 7.6.2.1 - secure_firewall_threat_defense = 7.7.0 - secure_firewall_threat_defense = 7.7.10 - secure_firewall_threat_defense = 7.7.10.1 - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.9.4 - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.9.5e - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.1a - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.2 - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.3 - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.3a - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.4 - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.4a - unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.4b patched: - snort 3.9.3.0 published: '2026-03-04' updated: '2026-08-20' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20053' references: - url: >- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3-vbavuls-96UcVVed label: psirt@cisco.com - url: 'https://software.cisco.com' tags: - nvd - csaf - vendor-advisory - cisco epss: 0.00439 epssPercentile: 0.3801 ingestedAt: '2026-08-20T17:59:04.119Z' --- ## Overview Multiple Cisco products are affected by a vulnerability in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash. This vulnerability is due to improper range checking when decompressing VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine on the targeted device. A successful exploit could allow the attacker to cause an overflow of heap data, which could cause a DoS condition. ## Affected - `snort >= 3.0.0-233, < 3.9.3.0` - `cyber_vision = 3.0.0` - `cyber_vision = 3.0.1` - `cyber_vision = 3.0.2` - `cyber_vision = 3.0.3` - `cyber_vision = 3.0.4` - `cyber_vision = 3.0.5` - `cyber_vision = 3.0.6` - `cyber_vision = 3.1.0` - `cyber_vision = 3.1.1` - `cyber_vision = 3.1.2` - `cyber_vision = 3.2.0` - `cyber_vision = 3.2.1` - `cyber_vision = 3.2.2` - `cyber_vision = 3.2.3` - `cyber_vision = 3.2.4` - `cyber_vision = 4.0.0` - `cyber_vision = 4.0.1` - `cyber_vision = 4.0.2` - `cyber_vision = 4.0.3` - `cyber_vision = 4.1.0` - `cyber_vision = 4.1.1` - `cyber_vision = 4.1.2` - `cyber_vision = 4.1.3` - `cyber_vision = 4.1.4` - `cyber_vision = 4.1.5` - `cyber_vision = 4.1.6` - `cyber_vision = 4.1.7` - `cyber_vision = 4.2.0` - `cyber_vision = 4.2.1` - `cyber_vision = 4.2.2` - `cyber_vision = 4.2.3` - `cyber_vision = 4.2.4` - `cyber_vision = 4.2.6` - `cyber_vision = 4.3.0` - `cyber_vision = 4.3.1` - `cyber_vision = 4.3.2` - `cyber_vision = 4.3.3` - `cyber_vision = 4.4.0` - `cyber_vision = 4.4.1` - `cyber_vision = 4.4.2` - `cyber_vision = 4.4.3` - `cyber_vision = 5.0.0` - `cyber_vision = 5.0.1` - `cyber_vision = 5.0.2` - `cyber_vision = 5.1.0` - `cyber_vision = 5.1.1` - `cyber_vision = 5.1.2` - `cyber_vision = 5.1.3` - `cyber_vision = 5.2.0` - `cyber_vision = 5.2.1` - `cyber_vision = 5.3.0` - `cyber_vision = 5.3.1` - `cyber_vision = 5.3.2` - `secure_firewall_threat_defense = 7.2.0` - `secure_firewall_threat_defense = 7.2.0.1` - `secure_firewall_threat_defense = 7.2.1` - `secure_firewall_threat_defense = 7.2.2` - `secure_firewall_threat_defense = 7.2.3` - `secure_firewall_threat_defense = 7.2.4` - `secure_firewall_threat_defense = 7.2.4.1` - `secure_firewall_threat_defense = 7.2.5` - `secure_firewall_threat_defense = 7.2.5.1` - `secure_firewall_threat_defense = 7.2.5.2` - `secure_firewall_threat_defense = 7.2.6` - `secure_firewall_threat_defense = 7.2.7` - `secure_firewall_threat_defense = 7.2.8` - `secure_firewall_threat_defense = 7.2.8.1` - `secure_firewall_threat_defense = 7.2.9` - `secure_firewall_threat_defense = 7.2.10` - `secure_firewall_threat_defense = 7.2.10.2` - `secure_firewall_threat_defense = 7.3.0` - `secure_firewall_threat_defense = 7.3.1` - `secure_firewall_threat_defense = 7.3.1.1` - `secure_firewall_threat_defense = 7.3.1.2` - `secure_firewall_threat_defense = 7.4.0` - `secure_firewall_threat_defense = 7.4.1` - `secure_firewall_threat_defense = 7.4.1.1` - `secure_firewall_threat_defense = 7.4.2` - `secure_firewall_threat_defense = 7.4.2.1` - `secure_firewall_threat_defense = 7.4.2.2` - `secure_firewall_threat_defense = 7.4.2.3` - `secure_firewall_threat_defense = 7.4.2.4` - `secure_firewall_threat_defense = 7.4.3` - `secure_firewall_threat_defense = 7.6.0` - `secure_firewall_threat_defense = 7.6.1` - `secure_firewall_threat_defense = 7.6.2` - `secure_firewall_threat_defense = 7.6.2.1` - `secure_firewall_threat_defense = 7.7.0` - `secure_firewall_threat_defense = 7.7.10` - `secure_firewall_threat_defense = 7.7.10.1` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.9.4` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.9.5e` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.1a` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.2` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.3` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.3a` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.4` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.4a` - `unified_threat_defense_snort_intrusion_prevention_system_engine = 17.12.4b` ## Remediation Upgrade past the affected range: - `snort 3.9.3.0` ## Vendor advisories - **cisco-sa-ftd-snort3-vbavuls-96UcVVed** · Cisco · affected: Cisco Firepower 2100 Series, Cisco Firepower 1000 Series, Cisco 3000 Series Industrial Security Appliances (ISA), Cisco Firepower 9000 Series, Cisco Firepower 4100 Series, Cisco Secure Firewall Threat Defense Virtual, … · updated 2026-03-04 · [advisory](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3-vbavuls-96UcVVed)