Allocation of Resources Without Limits or Throttling Affecting python-tornado package, versions <6.5.5-5ubuntu1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.42% (35th percentile)

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  • Snyk IDSNYK-UBUNTU2610-PYTHONTORNADO-21239156
  • published18 Oct 2026
  • disclosed15 Sept 2026

Introduced: 15 Sep 2026

CVE-2026-91990  (opens in a new tab)
CWE-770  (opens in a new tab)

How to fix?

Upgrade Ubuntu:26.10 python-tornado to version 6.5.5-5ubuntu1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python-tornado package and not the python-tornado package as distributed by Ubuntu. See How to fix? for Ubuntu:26.10 relevant fixed versions and status.

Tornado before 6.5.8 contains a memory amplification vulnerability in parse_multipart_form_data that splits multipart data before validating the max_parts limit. Attackers can send crafted multipart requests with many parts to create large transient lists, exhausting server memory and causing denial of service.

CVSS Base Scores

version 3.1