Cisco Secure Firewall Threat Defense Software HTTP resource consumption

Summaryinfo

A vulnerability, which was classified as problematic, was found in Cisco Secure Firewall Threat Defense Software and UTD SNORT IPS Engine Software. Impacted is an unknown function of the component HTTP Handler. Executing a manipulation can lead to resource consumption. This vulnerability is handled as CVE-2026-20066. The attack can be executed remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Cisco Secure Firewall Threat Defense Software and UTD SNORT IPS Engine Software (affected version not known) and classified as problematic. This vulnerability affects some unknown functionality of the component HTTP Handler. The manipulation with an unknown input leads to a resource consumption vulnerability. The CWE definition for the vulnerability is CWE-400. The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources. As an impact it is known to affect availability. CVE summarizes:

Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly. JSTokenizer is not enabled by default.

The advisory is available at sec.cloudapps.cisco.com. This vulnerability was named CVE-2026-20066 since 10/08/2025. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 03/05/2026). This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading eliminates this vulnerability.

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Productinfo

Type

• Firewall Software

Vendor

• Cisco

Name

• Secure Firewall Threat Defense Software
• UTD SNORT IPS Engine Software

License

• commercial

Website

• Vendor: https://www.cisco.com/

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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