Cisco Secure Firewall Threat Defense Software up to 7.7.10.1 SSL Decryption Policy denial of service

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Cisco Secure Firewall Threat Defense Software. Affected by this issue is some unknown functionality of the component SSL Decryption Policy. This manipulation causes denial of service. This vulnerability is handled as CVE-2026-20050. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Cisco Secure Firewall Threat Defense Software. It has been declared as problematic. Affected by this vulnerability is an unknown functionality of the component SSL Decryption Policy. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

A vulnerability in the Do Not Decrypt exclusion feature of the SSL decryption feature of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper memory management during the inspection of TLS 1.2 encrypted traffic. An attacker could exploit this vulnerability by sending crafted TLS 1.2 encrypted traffic through an affected device. A successful exploit could allow the attacker to cause a reload of an affected device. Note: This vulnerability only affects traffic that is encrypted by TLS 1.2. Other versions of TLS are not affected.

It is possible to read the advisory at sec.cloudapps.cisco.com. This vulnerability is known as CVE-2026-20050 since 10/08/2025. The exploitation appears to be difficult. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 03/04/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• Secure Firewall Threat Defense Software

Version

• 7.0.0
• 7.0.0.1
• 7.0.1
• 7.0.1.1
• 7.0.2
• 7.0.2.1
• 7.0.3
• 7.0.4
• 7.0.5
• 7.0.6
• 7.0.6.1
• 7.0.6.2
• 7.0.6.3
• 7.0.7
• 7.0.8
• 7.0.8.1
• 7.0.9
• 7.1.0
• 7.1.0.1
• 7.1.0.2
• 7.1.0.3
• 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
• 7.4.3
• 7.6.0
• 7.6.1
• 7.6.2
• 7.6.2.1
• 7.7.0
• 7.7.10
• 7.7.10.1

License

• commercial

Website

• Vendor: https://www.cisco.com/

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