CVE-2026-20218Cisco Secure Firewall Threat Defense Snort 3 Visual Basic for Applications Buffer Overflow Denial of Service Vulnerability
Updated under an hour ago ()
Does this affect you?
It affects Cisco Open Source Snort3 and 2 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 5.8 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
- Weakness (CWE)
- CWE-121
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- cisco
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 21, 2026
- First seen by InfoSec Signals
- Oct 21, 2026
Affected products
Cisco Cisco Open Source Snort3 cisco:open_source_snort3 (from the name) | 3.12.2.0; 3.1.2.0; 3.1.3.0; 3.1.4.0; 3.1.5.0; 3.1.6.0; 3.1.7.0; 3.1.8.0; and 97 more ranges | CNA record |
Cisco Cisco Secure Firewall Threat Defense (FTD) Software cisco:secure_firewall_threat_defense_ftd_software (from the name) | 7.2.0; 7.2.0.1; 7.2.1; 7.3.0; 7.2.2; 7.2.3; 7.3.1; 7.2.4; and 35 more ranges | CNA record |
Cisco Cisco UTD SNORT IPS Engine Software cisco:utd_snort_ips_engine_software (from the name) | 17.12.1a; 17.12.2; 17.13.1a; 17.12.3; 17.14.1a; 17.12.4; 17.12.3a; 17.15.1a; and 30 more ranges | CNA record |
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-vba-bufdos-jAuFdvn9
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.