What’s Vulnerable › Vulnerabilities
CVE-2026-20058: Cisco Secure Firewall Threat Defense Software Snort 3 Visual Basic for Application Denial of Service Vulnerability
- Severity: medium (CVSS 5.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-04 · updated 2026-08-20
- Weakness: CWE-786
Description
Multiple Cisco products are affected by vulnerabilities in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash. These vulnerabilities are due to improper error checking when decompressing VBA data. An attacker could exploit these vulnerabilities by sending crafted VBA data to the Snort 3 Detection Engine on the targeted device. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to unexpectedly restart, causing a DoS condition.
Affected products
- Cisco Firepower Threat Defense Software: 7.2.0, 7.2.0.1, 7.2.1, 7.2.2, 7.2.3, 7.2.4 (+31)
- Cisco Snort: from 3.0.0-233 before 3.9.6.0 — fixed in 3.9.6.0
- Cisco UTD SNORT IPS Engine Software: 17.9.3a, 17.9.5a, 17.9.6, 17.12.1a, 17.12.2, 17.12.3 (+24)
How to fix
Upgrade to a fixed version: Cisco Snort 3.9.6.0. Check the vendor advisory for mitigations.
References
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