CVE-2026-20218: Cisco Secure Firewall Threat Defense Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability
Cisco · Cisco Open Source Snort3
Affected: Cisco Open Source Snort3 · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 50% of scored CVEs
DescriptionCVE.org
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.
Affected products3
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Cisco · Cisco Open Source Snort33.12.2.0; 3.1.2.0; 3.1.3.0; 3.1.4.0; 3.1.5.0; 3.1.6.0 and 99 more
- Cisco · Cisco Secure Firewall Threat Defense (FTD) Software7.2.0; 7.2.0.1; 7.2.1; 7.3.0; 7.2.2; 7.2.3 and 37 more
- Cisco · Cisco UTD SNORT IPS Engine Software17.12.1a; 17.12.2; 17.13.1a; 17.12.3; 17.14.1a; 17.12.4 and 32 more
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- Cisco
- Published
- October 2026
CoverageNo articles yet
No CyberSIXT article names CVE-2026-20218 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.