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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Cisco Cisco Open Source Snort3 unknown
Version Status Constraints
3.1.2.0 affected —
3.1.3.0 affected —
3.1.4.0 affected —
3.1.5.0 affected —
3.1.6.0 affected —
3.1.7.0 affected —
3.1.8.0 affected —
3.1.9.0 affected —
3.1.10.0 affected —
3.1.12.0 affected —
3.1.13.0 affected —
3.1.14.0 affected —
3.1.15.0 affected —
3.1.16.0 affected —
3.1.17.0 affected —
3.1.18.0 affected —
3.1.19.0 affected —
3.1.20.0 affected —
3.1.21.0 affected —
3.1.22.0 affected —
3.1.23.0 affected —
3.1.24.0 affected —
3.1.25.0 affected —
3.1.27.0 affected —
3.1.28.0 affected —
3.1.29.0 affected —
3.1.30.0 affected —
3.1.31.0 affected —
3.1.32.0 affected —
3.1.36.0 affected —
3.1.38.0 affected —
3.1.39.0 affected —
3.1.40.0 affected —
3.1.41.0 affected —
3.1.42.0 affected —
3.1.43.0 affected —
3.1.45.0 affected —
3.1.47.0 affected —
3.1.48.0 affected —
3.1.50.0 affected —
3.1.51.0 affected —
3.1.52.0 affected —
3.1.53.0 affected —
3.1.55.0 affected —
3.1.56.0 affected —
3.1.57.0 affected —
3.1.58.0 affected —
3.1.59.0 affected —
3.1.60.0 affected —
3.1.61.0 affected —
3.1.62.0 affected —
3.1.63.0 affected —
3.1.64.0 affected —
3.1.65.0 affected —
3.1.66.0 affected —
3.1.67.0 affected —
3.1.69.0 affected —
3.1.70.0 affected —
3.1.71.0 affected —
3.1.72.0 affected —
3.1.73.0 affected —
3.1.74.0 affected —
3.1.75.0 affected —
3.1.76.0 affected —
3.1.77.0 affected —
3.1.78.0 affected —
3.1.81.0 affected —
3.1.82.0 affected —
3.1.83.0 affected —
3.1.84.0 affected —
3.2.1.0 affected —
3.2.2.0 affected —
3.3.0.0 affected —
3.3.1.0 affected —
3.3.2.0 affected —
3.3.3.0 affected —
3.3.4.0 affected —
3.3.5.0 affected —
3.3.7.0 affected —
3.5.0.0 affected —
3.5.1.0 affected —
3.8.1.0 affected —
3.6.0.0 affected —
3.6.2.0 affected —
3.9.3.0 affected —
3.7.2.0 affected —
3.7.0.0 affected —
3.9.6.0 affected —
3.10.0.0 affected —
3.7.4.0 affected —
3.9.0.0 affected —
3.5.2.0 affected —
3.6.1.0 affected —
3.9.2.0 affected —
3.6.3.0 affected —
3.9.5.0 affected —
3.7.1.0 affected —
3.9.7.0 affected —
3.7.3.0 affected —
3.9.1.0 affected —
Cisco Cisco Secure Firewall Threat Defense (FTD) Software unknown
Version Status Constraints
7.0.0 affected —
7.0.0.1 affected —
7.0.1 affected —
7.0.1.1 affected —
7.0.2 affected —
7.2.0 affected —
7.0.2.1 affected —
7.0.3 affected —
7.2.0.1 affected —
7.0.4 affected —
7.2.1 affected —
7.0.5 affected —
7.3.0 affected —
7.2.2 affected —
7.2.3 affected —
7.3.1 affected —
7.2.4 affected —
7.0.6 affected —
7.2.5 affected —
7.2.4.1 affected —
7.3.1.1 affected —
7.4.0 affected —
7.0.6.1 affected —
7.2.5.1 affected —
7.4.1 affected —
7.2.6 affected —
7.0.6.2 affected —
7.4.1.1 affected —
7.2.7 affected —
7.2.5.2 affected —
7.3.1.2 affected —
7.2.8 affected —
7.6.0 affected —
7.4.2 affected —
7.2.8.1 affected —
7.0.6.3 affected —
7.4.2.1 affected —
7.2.9 affected —
7.0.7 affected —
7.7.0 affected —
7.4.2.2 affected —
7.2.10 affected —
7.6.1 affected —
7.4.2.3 affected —
7.0.8 affected —
7.6.2 affected —
7.7.10 affected —
7.7.11 affected —
7.0.8.1 affected —
7.6.2.1 affected —
7.7.10.1 affected —
7.4.2.4 affected —
7.2.10.2 affected —
7.4.3 affected —
7.6.4 affected —
10.0.0 affected —
7.4.4 affected —
7.0.9 affected —
7.2.11 affected —
Cisco Cisco UTD SNORT IPS Engine Software unknown
Version Status Constraints
3.17.1S affected —
16.12.3 affected —
Fuji-16.9.5 affected —
16.12.4 affected —
17.3.1a affected —
16.6.6 affected —
16.12.2 affected —
Fuji-16.9.6 affected —
3.17.0S affected —
Fuji-16.9.3 affected —
Denali-16.3.7 affected —
Fuji-16.9.2 affected —
Fuji-16.9.4 affected —
Everest-16.6.4 affected —
Everest-16.6.3 affected —
16.6.5 affected —
Denali-16.3.5 affected —
17.2.1r affected —
17.1.1 affected —
Everest-16.6.2 affected —
16.6.7a affected —
Denali-16.3.4 affected —
16.6.1 affected —
Denali-16.3.9 affected —
Denali-16.3.3 affected —
16.12.1a affected —
17.3.2 affected —
17.4.1a affected —
16.12.5 affected —
Fuji-16.9.7 affected —
16.6.9 affected —
17.3.3 affected —
17.5.1a affected —
17.3.4a affected —
17.4.2 affected —
17.4.1b affected —
17.6.1a affected —
16.6.10 affected —
17.7.1a affected —
16.12.6 affected —
Fuji-16.9.8 affected —
17.6.2 affected —
17.8.1a affected —
16.12.7 affected —
17.3.5 affected —
17.6.3a affected —
17.7.2 affected —
17.9.1a affected —
17.6.4 affected —
17.10.1a affected —
17.3.6 affected —
16.12.8 affected —
17.3.7 affected —
17.9.2a affected —
17.6.5 affected —
17.11.1a affected —
17.9.3a affected —
17.12.1a affected —
17.9.4 affected —
17.6.6 affected —
17.3.8 affected —
17.12.2 affected —
17.13.1a affected —
17.9.5a affected —
17.12.3 affected —
17.6.7 affected —
17.14.1a affected —
17.12.4 affected —
17.12.3a affected —
17.15.1a affected —
17.9.6 affected —
17.6.8a affected —
17.16.1a affected —
17.9.5e affected —
17.12.4a affected —
17.15.2c affected —
17.9.5f affected —
17.12.4b affected —
17.15.2a affected —
17.12.5 affected —
17.17.1 affected —
17.12.5a affected —
17.9.7a affected —
17.15.3a affected —
17.15.3 affected —
17.12.5b affected —
17.12.5c affected —
17.15.4 affected —
17.9.7b affected —
17.18.1 affected —
17.18.1a affected —
17.12.6 affected —
17.9.8 affected —
17.15.4c affected —
17.12.5d affected —
17.18.2 affected —
26.1.1 affected —
17.15.5 affected —
17.15.5a affected —
17.12.7 affected —
17.12.7a affected —
17.12.7b affected —
17.9.9 affected —
17.12.8 affected —
17.15.6 affected —
17.18.4 affected —
26.1.2 affected —

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-mime-vulns-bkXjcKkt cve-icon cve-icon
History

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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

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

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

Link: CVE-2026-20011

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

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

Modified: 2026-10-21T18:54:37.403

Link: CVE-2026-20011

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-21T20:45:14Z

Weaknesses