CVE-2026-20290
published 2026-09-16CVE-2026-20290: A vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an…
PriorityP432medium5.8CVSS 3.1
AVNACLPRNUINSCCNINAL
EPSS
0.19%
8.2th percentile
A vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 2 Detection Engine to restart.
This vulnerability is due to incomplete validation of the SSL certificate. An attacker could exploit this vulnerability by sending a crafted SSL connection setup request to be parsed by Snort 2. A successful exploit could allow the attacker to cause the Snort 2 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.
Affected
55 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
| cisco | cisco_secure_firewall_threat_defense_software | — | — |
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GHSA
A vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort
ghsa_unreviewed·2026-09-16
CVE-2026-20290 [MEDIUM] CWE-805 A vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort
A vulnerability in SSL/TLS certificate parsing in the Snort 2 Detection Engine of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the Snort 2 Detection Engine to restart.
This vulnerability is due to incomplete validation of the SSL certificate. An attacker could exploit this vulnerability by sending a crafted SSL connection setup request to be parsed by Snort 2. A successful exploit could allow the attacker to cause the Snort 2 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition.
VulDB
Cisco Secure Firewall Threat Defense up to 7.6.4 Snort 2 Detection Engine resource consumption
vuldb·2026-09-16·CVSS 5.8
CVE-2026-20290 [MEDIUM] Cisco Secure Firewall Threat Defense up to 7.6.4 Snort 2 Detection Engine resource consumption
A vulnerability categorized as critical has been discovered in Cisco Secure Firewall Threat Defense. Affected is an unknown function of the component Snort 2 Detection Engine. The manipulation results in resource consumption.
This vulnerability was named CVE-2026-20290. The attack may be performed from remote. There is no available exploit.
It is advisable to upgrade the affected component.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-09-16
Published