CVE-2026-31958

Aliases:GHSA-qjxf-f2mg-c6mcECHO-5939-f806-1836PYSEC-2026-140RHSA-2026:8093UBUNTU-CVE-2026-31958DEBIAN-CVE-2026-31958CGA-5v8v-h3h5-v3v3CGA-7gxv-rwrh-r7c6CGA-cjf5-m5rr-ch9fCGA-mf8j-7mxw-vmpwCGA-35vc-6wh6-wrm4CGA-8f39-wqpq-8m7mCGA-9wqx-wfjf-pqj8CGA-frvg-4p65-jc47CGA-hjpx-83gg-p58qCGA-q68q-5qr8-pf57CGA-qx4q-gvh7-9wmwCGA-r7hh-wv29-xvr8CGA-x86g-hx9q-qwfp
Advisory lineage Upstream: 0 Downstream: 35
Modified
Published: 11 Mar 2026, 19:27
Last modified:01 Apr 2026, 14:32

Vulnerability Summary

Overall Risk (default)
medium
35/100
CVSS Score
8.7 HIGH
v4.0 (cve.org)
EPSS Score
0.38% LOW
0% probability +0.35%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

11 Mar 2026, 19:27
Published
Vulnerability first disclosed
01 Apr 2026, 14:32
Last Modified
Vulnerability information updated

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

  • v4.0•HIGH•Score: 8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
  • v4.0•HIGH•Score: 8.7CVSS: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
  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
  • v3.1•MEDIUM•Score: 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

EPSS Trends

Current EPSS score: 0.38%• Percentile: 31%

Techniques & Countermeasures

  • CWE-400•Uncontrolled Resource Consumption

    The product does not properly control the allocation and maintenance of a limited resource.

Affected Systems

  • chainguard•airflow-2

    < 2.11.2-r1

  • chainguard•airflow-3

    < 3.1.8-r2

  • chainguard•dask-kubernetes

    < 2026.3.0-r1

  • chainguard•kubeflow-pipelines-visualization-server

    < 2.16.0-r2

  • chainguard•litellm

    < 1.81.14-r1

  • chainguard•mitmproxy

    < 12.2.2-r1

  • chainguard•tensorflow-cpu-jupyter

    < 2.21.0-r1

  • chainguard•tensorflow-gpu-jupyter

    < 2.21.0-r1

  • wolfi•airflow-3

    < 3.1.8-r2

  • wolfi•dask-kubernetes

    < 2026.3.0-r1

  • wolfi•kubeflow-pipelines-visualization-server

    < 2.16.0-r2

  • wolfi•mitmproxy

    < 12.2.2-r1

  • debian•python-tornado

    < 6.1.0-1+deb11u4 | all | all | < 6.5.5-1

  • ubuntu•python-tornado

    < 4.2.1-1ubuntu3.1+esm3 | < 4.5.3-1ubuntu0.2+esm3 | < 6.1.0-3ubuntu0.1~esm5 | < 6.4.0-1ubuntu0.5 | < 6.4.2-3ubuntu0.3 | < 6.5.4-0.1ubuntu0.1

  • PyPI•tornado

    < 6.5.5

  • redhat•pcs

    < 0:0.10.18-2.el8_10.9 | < 0:0.10.18-2.el8_10.9

  • redhat•pcs-snmp

    < 0:0.10.18-2.el8_10.9 | < 0:0.10.18-2.el8_10.9

  • tornadoweb•tornado

    < 6.5.5

References (18)