{"id":"CVE-2026-20006","title":"A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpec…","summary":"A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpec…","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-388"],"vendor":"cisco","product":"secure_firewall_threat_defense","affected":["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 = 7.6.0","secure_firewall_threat_defense = 7.6.1","secure_firewall_threat_defense = 7.6.2","secure_firewall_threat_defense = 7.6.2.1"],"published":"2026-03-04","updated":"2026-08-20","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-20006","references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tcp-dos-rHfqnwRg","label":"psirt@cisco.com"}],"tags":["nvd"],"epss":0.00373,"epssPercentile":0.3107,"ingestedAt":"2026-08-20T17:59:03.999Z","slug":"CVE-2026-20006","body":"## Overview\n\nA vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpectedly restart, resulting in a denial of service (DoS) condition.\r\n\r\nThis vulnerability is due to improper implementation of the TLS protocol. An attacker could exploit this vulnerability by sending a crafted TLS packet to an affected system. A successful exploit could allow the attacker to cause a device that is running Cisco Secure FTD Software to drop network traffic, resulting in a DoS condition. \r\nNote: TLS 1.3 is not affected by this vulnerability.\n\n## Affected\n\n- `secure_firewall_threat_defense = 7.2.0`\n- `secure_firewall_threat_defense = 7.2.0.1`\n- `secure_firewall_threat_defense = 7.2.1`\n- `secure_firewall_threat_defense = 7.2.2`\n- `secure_firewall_threat_defense = 7.2.3`\n- `secure_firewall_threat_defense = 7.2.4`\n- `secure_firewall_threat_defense = 7.2.4.1`\n- `secure_firewall_threat_defense = 7.2.5`\n- `secure_firewall_threat_defense = 7.2.5.1`\n- `secure_firewall_threat_defense = 7.2.5.2`\n- `secure_firewall_threat_defense = 7.2.6`\n- `secure_firewall_threat_defense = 7.2.7`\n- `secure_firewall_threat_defense = 7.2.8`\n- `secure_firewall_threat_defense = 7.2.8.1`\n- `secure_firewall_threat_defense = 7.2.9`\n- `secure_firewall_threat_defense = 7.2.10`\n- `secure_firewall_threat_defense = 7.2.10.2`\n- `secure_firewall_threat_defense = 7.3.0`\n- `secure_firewall_threat_defense = 7.3.1`\n- `secure_firewall_threat_defense = 7.3.1.1`\n- `secure_firewall_threat_defense = 7.3.1.2`\n- `secure_firewall_threat_defense = 7.4.0`\n- `secure_firewall_threat_defense = 7.4.1`\n- `secure_firewall_threat_defense = 7.4.1.1`\n- `secure_firewall_threat_defense = 7.4.2`\n- `secure_firewall_threat_defense = 7.4.2.1`\n- `secure_firewall_threat_defense = 7.4.2.2`\n- `secure_firewall_threat_defense = 7.4.2.3`\n- `secure_firewall_threat_defense = 7.4.2.4`\n- `secure_firewall_threat_defense = 7.6.0`\n- `secure_firewall_threat_defense = 7.6.1`\n- `secure_firewall_threat_defense = 7.6.2`\n- `secure_firewall_threat_defense = 7.6.2.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":32,"depthScoreParts":{"impact":31.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}