{"id":"CVE-2026-20218","aliases":["EUVD-2026-107375","GHSA-vvhg-cxrm-qp98"],"status":"published","title":"Cisco Secure Firewall Threat Defense Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability","description":"A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of multiple Cisco products could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.\u0026nbsp;\u0026nbsp;\r\n\r\nThis vulnerability is due to improper range checking when Snort 3 decompresses VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine of a targeted device. A successful exploit could allow the attacker to cause an overflow of stack data, which could result in a DoS condition.","severity":{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.0063,"percentile":0.50507,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-121"],"published":"2026-10-21T16:12:38Z","modified":"2026-10-22T19:17:51Z","products":[{"vendor":"cisco","product":"cisco open source snort3"},{"vendor":"cisco","product":"cisco secure firewall threat defense (ftd) software"},{"vendor":"cisco","product":"cisco utd snort ips engine software"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-vba-bufdos-jAuFdvn9"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-20218"},{"url":"https://github.com/advisories/GHSA-vvhg-cxrm-qp98"}],"sources":{"cve":[{"id":"CVE-2026-20218","title":"Cisco Secure Firewall Threat Defense Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability","description":"A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of multiple Cisco products could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.\u0026nbsp;\u0026nbsp;\r\n\r\nThis vulnerability is due to improper range checking when Snort 3 decompresses VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine of a targeted device. A successful exploit could allow the attacker to cause an overflow of stack data, which could result in a DoS condition.","status":"published","published":"2026-10-21T16:12:38.494Z","modified":"2026-10-22T19:11:10.095Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-121"],"updated_at":"2026-11-02T13:35:44.571002Z"}],"euvd":[{"id":"EUVD-2026-107375","description":"A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of multiple Cisco products could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.\u0026nbsp;\u0026nbsp;\r\n\r\nThis vulnerability is due to improper range checking when Snort 3 decompresses VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine of a targeted device. A successful exploit could allow the attacker to cause an overflow of stack data, which could result in a DoS condition.","status":"published","published":"2026-10-21T16:12:38Z","modified":"2026-10-22T19:11:10Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-02T16:59:34.021826Z"}],"ghsa":[{"id":"GHSA-vvhg-cxrm-qp98","title":"A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of...","description":"A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of multiple Cisco products could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.\n\nThis vulnerability is due to improper range checking when Snort 3 decompresses VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine of a targeted device. A successful exploit could allow the attacker to cause an overflow of stack data, which could result in a DoS condition.","status":"published","published":"2026-10-21T18:33:17Z","modified":"2026-10-21T18:33:24Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-121"],"updated_at":"2026-11-02T15:14:13.106716Z"}],"nvd":[{"id":"CVE-2026-20218","description":"A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of multiple Cisco products could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.\u0026nbsp;\u0026nbsp;\r\n\r\nThis vulnerability is due to improper range checking when Snort 3 decompresses VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine of a targeted device. A successful exploit could allow the attacker to cause an overflow of stack data, which could result in a DoS condition.","status":"published","published":"2026-10-21T17:18:27.733Z","modified":"2026-10-22T19:17:51.96Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-121"],"updated_at":"2026-11-02T14:13:02.371082Z"}]}}