What’s Vulnerable › Vulnerabilities
CVE-2026-20006: Cisco Firepower Threat Defense Software and Cisco FirePOWER Services TLS with Snort 3 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-388
Description
A vulnerability in the TLS cryptography functionality of the Snort 3 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to unexpectedly restart, resulting in a denial of service (DoS) condition. This vulnerability is due to improper implementation of the TLS protocol. An attacker could exploit this vulnerability by sending a crafted TLS packet to an affected system. A successful exploit could allow the attacker to cause a device that is running Cisco Secure FTD Software to drop network traffic, resulting in a DoS condition. Note: TLS 1.3 is not affected by this vulnerability.
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 (+27)
References
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