CVE-2026-20290 PUBLISHED

Cisco Secure Firewall Threat Defense Software Snort 2 SSL/TLS Denial of Service Vulnerability

Assigner: cisco
Reserved: 08.10.2025 Published: 16.09.2026 Updated: 16.09.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
CVSS Score: 5.8

Product Status

Vendor Cisco
Product Cisco Secure Firewall Threat Defense (FTD) Software
Versions Default: unknown
  • Version 7.0.0 is affected
  • Version 7.0.0.1 is affected
  • Version 7.0.1 is affected
  • Version 7.0.1.1 is affected
  • Version 7.0.2 is affected
  • Version 7.2.0 is affected
  • Version 7.0.2.1 is affected
  • Version 7.0.3 is affected
  • Version 7.2.0.1 is affected
  • Version 7.0.4 is affected
  • Version 7.2.1 is affected
  • Version 7.0.5 is affected
  • Version 7.3.0 is affected
  • Version 7.2.2 is affected
  • Version 7.2.3 is affected
  • Version 7.3.1 is affected
  • Version 7.2.4 is affected
  • Version 7.0.6 is affected
  • Version 7.2.5 is affected
  • Version 7.2.4.1 is affected
  • Version 7.3.1.1 is affected
  • Version 7.4.0 is affected
  • Version 7.0.6.1 is affected
  • Version 7.2.5.1 is affected
  • Version 7.4.1 is affected
  • Version 7.2.6 is affected
  • Version 7.0.6.2 is affected
  • Version 7.4.1.1 is affected
  • Version 7.2.7 is affected
  • Version 7.2.5.2 is affected
  • Version 7.3.1.2 is affected
  • Version 7.2.8 is affected
  • Version 7.6.0 is affected
  • Version 7.4.2 is affected
  • Version 7.2.8.1 is affected
  • Version 7.0.6.3 is affected
  • Version 7.4.2.1 is affected
  • Version 7.2.9 is affected
  • Version 7.0.7 is affected
  • Version 7.4.2.2 is affected
  • Version 7.2.10 is affected
  • Version 7.6.1 is affected
  • Version 7.4.2.3 is affected
  • Version 7.0.8 is affected
  • Version 7.6.2 is affected
  • Version 7.0.8.1 is affected
  • Version 7.6.2.1 is affected
  • Version 7.4.2.4 is affected
  • Version 7.2.10.2 is affected
  • Version 7.4.3 is affected
  • Version 7.6.4 is affected
  • Version 7.4.4 is affected
  • Version 7.0.9 is affected
  • Version 7.2.11 is affected
  • Version 7.4.7 is affected

Exploits

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References

Problem Types

  • Buffer Access with Incorrect Length Value cwe