Multiple Cisco products are affected by a vulnerability in the Snort 3 SMTP MIME Decoder that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. This vulnerability is due to a lack of error checking when the MIME fields of the SMTP header are parsed. An attacker could exploit this vulnerability by sending crafted SMTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine unexpectedly restarts.
History

Sat, 24 Oct 2026 05:15:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco cisco Open Source Snort3
Cisco cisco Secure Firewall Threat Defense (ftd) Software
Cisco cisco Utd Snort Ips Engine Software
Cisco secure Firewall Threat Defense
Vendors & Products Cisco
Cisco cisco Open Source Snort3
Cisco cisco Secure Firewall Threat Defense (ftd) Software
Cisco cisco Utd Snort Ips Engine Software
Cisco secure Firewall Threat Defense

Thu, 22 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 21 Oct 2026 17:15:00 +0000

Type Values Removed Values Added
Description Multiple Cisco products are affected by a vulnerability in the Snort 3 SMTP MIME Decoder that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart. This vulnerability is due to a lack of error checking when the MIME fields of the SMTP header are parsed. An attacker could exploit this vulnerability by sending crafted SMTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a denial of service (DoS) condition when the Snort 3 Detection Engine unexpectedly restarts.
Title Multiple Cisco Products Snort 3 SMTP MIME Denial of Service Vulnerability
Weaknesses CWE-805
References
Metrics cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2026-10-21T16:12:19.429Z

Updated: 2026-10-22T19:11:17.797Z

Reserved: 2025-10-08T11:59:15.350Z

Link: CVE-2026-20011

cve-icon Vulnrichment

Updated: 2026-10-22T13:37:39.590Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-21T17:18:26.640

Modified: 2026-10-22T14:17:39.607

Link: CVE-2026-20011

cve-icon Redhat

No data.