Cisco Secure Firewall Threat Defense Software up to 7.6.2.1 TLS Protocol 7pk error

Summaryinfo

A vulnerability was found in Cisco Secure Firewall Threat Defense Software and classified as problematic. Affected by this issue is some unknown functionality of the component TLS Protocol Handler. Such manipulation leads to 7pk error. This vulnerability is referenced as CVE-2026-20006. It is possible to launch the attack remotely. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cisco Secure Firewall Threat Defense Software and classified as problematic. Affected by this issue is an unknown code of the component TLS Protocol Handler. The manipulation with an unknown input leads to a 7pk error vulnerability. Using CWE to declare the problem leads to CWE-388. Impacted is availability. CVE summarizes:

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.

The advisory is shared for download at sec.cloudapps.cisco.com. This vulnerability is handled as CVE-2026-20006 since 10/08/2025. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 03/05/2026).

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• Secure Firewall Threat Defense Software

Version

• 7.2.0
• 7.2.0.1
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.2.4.1
• 7.2.5
• 7.2.5.1
• 7.2.5.2
• 7.2.6
• 7.2.7
• 7.2.8
• 7.2.8.1
• 7.2.9
• 7.2.10
• 7.2.10.2
• 7.3.0
• 7.3.1
• 7.3.1.1
• 7.3.1.2
• 7.4.0
• 7.4.1
• 7.4.1.1
• 7.4.2
• 7.4.2.1
• 7.4.2.2
• 7.4.2.3
• 7.4.2.4
• 7.6.0
• 7.6.1
• 7.6.2
• 7.6.2.1

License

• commercial

Website

• Vendor: https://www.cisco.com/

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