Multiple Cisco Products Snort 3 DoS Vulnerabilities (cisco-sa-snort3-multi-dos-XFWkWSwz_CVE-2026-20066)

medium Nessus Plugin ID 301693

Synopsis

The remote device is missing a vendor-supplied security patch

Description

According to its self-reported version, Cisco ASA Software is affected by a vulnerability.

- 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. (CVE-2026-20066)

Please see the included Cisco BIDs and Cisco Security Advisory for more information.

Solution

Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCwn49805, CSCwn65473, CSCwo93207, CSCwo93208, CSCwp99280, CSCwq01529, CSCwq01530, CSCwq03411, CSCwq23374, CSCwq82404, CSCwq97624, CSCwq97644, CSCwq97649, CSCwr21398

Plugin Details

Severity: Medium

ID: 301693

File Name: cisco-sa-snort3-multi-dos-XFWkWSwz_CVE-2026-20066-asa.nasl

Version: 1.1

Type: local

Family: CISCO

Published: 3/10/2026

Updated: 3/10/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 2.4

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2026-20066

CVSS v3

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 5.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:cisco:adaptive_security_appliance_software

Required KB Items: Host/Cisco/ASA/model

Exploit Ease: No known exploits are available

Patch Publication Date: 3/4/2026

Vulnerability Publication Date: 3/4/2026

Reference Information

CVE: CVE-2026-20066

CWE: 248, 392, 400

CISCO-SA: cisco-sa-snort3-multi-dos-XFWkWSwz_CVE-2026-20066

CISCO-BUG-ID: CSCwn49805, CSCwn65473, CSCwo93207, CSCwo93208, CSCwp99280, CSCwq01529, CSCwq01530, CSCwq03411, CSCwq23374, CSCwq82404, CSCwq97624, CSCwq97644, CSCwq97649, CSCwr21398

Detections

Analytics