CVE-2026-20218 json
Cisco Secure Firewall Threat Defense Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability
published 2026-10-21 18 d ago modified 2026-10-22 17 d ago also EUVD-2026-107375
- cvss
- 5.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 50%
- public exploits
- 0
- none known
Summary
A vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine of multiple Cisco products could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.
This vulnerability is due to improper range checking when Snort 3 decompresses VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine of a targeted device. A successful exploit could allow the attacker to cause an overflow of stack data, which could result in a DoS condition.
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 18 d ago
Exploit prediction
0.63% chance of exploitation in the next 30 days, higher than 50% 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 Open Source Snort3
- Cisco Cisco Secure Firewall Threat Defense (FTD) Software
- Cisco Cisco UTD SNORT IPS Engine Software
Classification
- Weakness
-
- CWE-121 Stack-based Buffer Overflow
References
Sources
- CVE List CVE-2026-20218
- NVD CVE-2026-20218
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