Vulnerability · Published Mar 4, 2026 · Assigned by cisco
CVE-2026-20066Multiple Cisco Products Snort 3 TBD Denial of Service Vulnerability
Medium 5.8
In plain English
A medium-severity uncontrolled resource consumption in Cisco Secure Firewall Threat Defense (FTD) Software from Cisco. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities).
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 7.4.07.4.17.4.1.17.6.07.4.27.4.2.17.7.07.4.2.2 |
| Cisco | Cisco UTD SNORT IPS Engine Software | 17.3.1a17.2.1r17.3.217.4.1a17.5.117.3.317.5.1a17.3.4 |
Weakness: CWE-400 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L