tornadoweb tornado up to 6.5.4 resource consumption

Summaryinfo

A vulnerability, which was classified as problematic, was found in tornadoweb tornado up to 6.5.4. Affected by this vulnerability is an unknown functionality. Executing a manipulation can lead to resource consumption. This vulnerability appears as CVE-2026-31958. The attack may be performed from remote. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in tornadoweb tornado up to 6.5.4. It has been declared as problematic. This vulnerability affects some unknown functionality. 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:

Tornado is a Python web framework and asynchronous networking library. In versions of Tornado prior to 6.5.5, the only limit on the number of parts in multipart/form-data is the max_body_size setting (default 100MB). Since parsing occurs synchronously on the main thread, this creates the possibility of denial-of-service due to the cost of parsing very large multipart bodies with many parts. This vulnerability is fixed in 6.5.5.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-31958 since 03/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1499.

The vulnerability scanner Nessus provides a plugin with the ID 304850 (SUSE SLED15 / SLES15 Security Update : python-tornado (SUSE-SU-2026:1171-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.5.5 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (304850). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• tornadoweb

Name

• tornado

Version

• 6.5.0
• 6.5.1
• 6.5.2
• 6.5.3
• 6.5.4

Website

• Product: https://github.com/tornadoweb/tornado/

CPE 2.3info

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Once again VulDB remains the best source for vulnerability data.

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