CVE-2026-20053
Cisco Secure Firewall Threat Defense Software Snort 3 Visual Basic for Application Heap Overflow Denial of Service Vulnerability
Severity
Medium 5.8
CVSS 3.1
Exploited
Not listed
EPSS
0.004
34.0th percentile
Discovered by
Vendor
Published by the vendor
Published
Mar 4, 2026
Assigned by cisco
Description
Multiple Cisco products are affected by a vulnerability in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash. This vulnerability is due to improper range checking when decompressing VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine on the targeted device. A successful exploit could allow the attacker to cause an overflow of heap data, which could cause a DoS condition.
Weakness: CWE-122
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco Cyber Vision | OT / IoT Security | cna-assigner |
| Cisco | Cisco Secure Firewall | Firewall / NGFW | cna-assigner |
| Cisco | Cisco UTD SNORT IPS Engine | Threat Detection & Sandbox | cna-assigner |
Vendor-reported affected versions (3)
- Cisco · Cisco Cyber Vision
- Cisco · Cisco Secure Firewall Threat Defense (FTD) Software
- Cisco · Cisco UTD SNORT IPS Engine Software