CVE-2026-20066 json
Multiple Cisco Products Snort 3 TBD Denial of Service Vulnerability
published 2026-03-04 8 mo ago modified 2026-08-19 2 mo ago also EUVD-2026-9465
- cvss
- 5.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 44%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- cisco snort 3.9.7.0
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 8 mo ago
Exploit prediction
0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L |
Affected products
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software
- Cisco Cisco UTD SNORT IPS Engine Software
Classification
- Weakness
-
- CWE-400 Uncontrolled Resource Consumption
References
Sources
- CVE List CVE-2026-20066
- NVD CVE-2026-20066
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