CVE-2026-20006

Published: Mar 4, 2026Modified: Aug 20, 2026

5.8

Vector

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

Exploitability: 3.9 / Impact: 1.4

Source: psirt@cisco.com (Secondary)

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 (33)

Products: Cisco: Secure Firewall Threat Defense

Cisco

1 product

Secure Firewall Threat Defense

Configuration A

33 vulnerable

Vulnerable Software	Affected Versions
Cisco Secure Firewall Threat Defense	Version 7.2.0.1
Cisco Secure Firewall Threat Defense	Version 7.2.0
Cisco Secure Firewall Threat Defense	Version 7.2.10.2
Cisco Secure Firewall Threat Defense	Version 7.2.10
Cisco Secure Firewall Threat Defense	Version 7.2.1
Cisco Secure Firewall Threat Defense	Version 7.2.2
Cisco Secure Firewall Threat Defense	Version 7.2.3
Cisco Secure Firewall Threat Defense	Version 7.2.4.1
Cisco Secure Firewall Threat Defense	Version 7.2.4
Cisco Secure Firewall Threat Defense	Version 7.2.5.1
Cisco Secure Firewall Threat Defense	Version 7.2.5.2
Cisco Secure Firewall Threat Defense	Version 7.2.5
Cisco Secure Firewall Threat Defense	Version 7.2.6
Cisco Secure Firewall Threat Defense	Version 7.2.7
Cisco Secure Firewall Threat Defense	Version 7.2.8.1
Cisco Secure Firewall Threat Defense	Version 7.2.8
Cisco Secure Firewall Threat Defense	Version 7.2.9
Cisco Secure Firewall Threat Defense	Version 7.3.0
Cisco Secure Firewall Threat Defense	Version 7.3.1.1
Cisco Secure Firewall Threat Defense	Version 7.3.1.2
Cisco Secure Firewall Threat Defense	Version 7.3.1
Cisco Secure Firewall Threat Defense	Version 7.4.0
Cisco Secure Firewall Threat Defense	Version 7.4.1.1
Cisco Secure Firewall Threat Defense	Version 7.4.1
Cisco Secure Firewall Threat Defense	Version 7.4.2.1
Cisco Secure Firewall Threat Defense	Version 7.4.2.2
Cisco Secure Firewall Threat Defense	Version 7.4.2.3
Cisco Secure Firewall Threat Defense	Version 7.4.2.4
Cisco Secure Firewall Threat Defense	Version 7.4.2
Cisco Secure Firewall Threat Defense	Version 7.6.0
Cisco Secure Firewall Threat Defense	Version 7.6.1
Cisco Secure Firewall Threat Defense	Version 7.6.2.1
Cisco Secure Firewall Threat Defense	Version 7.6.2

Related CWEs

CWE-388

References (1)

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-tcp-dos-rHfqnwRg

Source: psirt@cisco.com

Vendor AdvisoryMitigation

Timeline

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