Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly. JSTokenizer is not enabled by default.

Metrics

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.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

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References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-multi-dos-XFWkWSwz cve-icon cve-icon
History

Wed, 04 Mar 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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

Wed, 04 Mar 2026 18:00:00 +0000

Type Values Removed Values Added
Description Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly. JSTokenizer is not enabled by default.
Title Multiple Cisco Products Snort 3 TBD Denial of Service Vulnerability
Weaknesses CWE-400
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: 2026-03-04T17:49:00.716Z

Updated: 2026-03-04T20:46:18.739Z

Reserved: 2025-10-08T11:59:15.357Z

Link: CVE-2026-20066

cve-icon Vulnrichment

Updated: 2026-03-04T20:46:13.165Z

cve-icon NVD

Status : Received

Published: 2026-03-04T18:16:21.670

Modified: 2026-03-04T18:16:21.670

Link: CVE-2026-20066

cve-icon Redhat

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