Is CVE-2026-31958 actively exploited?

CVE-2026-31958 has no public evidence of in-the-wild exploitation as of 2026-04-01.

What is the CVSS score for CVE-2026-31958?

CVE-2026-31958 has a CVSS score of 8.7 (HIGH severity). Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

How do I patch CVE-2026-31958?

Patch guidance is available from tornadoweb security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-31958.

Fix CVE-2026-31958 - HIGH tornadoweb tornado

Description

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.

CVSS Metrics

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-400

Metadata

Primary Vendor: TORNADOWEB
Published: 3/11/2026
Last Modified: 4/1/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

tornadoweb : tornado

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-31958. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-31958

View on NIST NVD

CVE-2026-31958 vulnerability