Use of Blocking Code in Single-threaded, Non-blocking Context Affecting python-tornado package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.38% (33rd percentile)

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  • Snyk IDSNYK-RHEL10-PYTHONTORNADO-21737329
  • published27 Oct 2026
  • disclosed26 Oct 2026

Introduced: 26 Oct 2026

NewCVE-2026-116577  (opens in a new tab)
CWE-1322  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 python-tornado.

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 RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

Tornado is a Python web framework and asynchronous networking library. Prior to 6.6, Tornado's HTTP header parser accepts obsolete line folding and repeatedly concatenates short continuation lines, causing quadratic CPU consumption on the IOLoop thread. An unauthenticated client can submit a header block containing many obsolete line-folding continuations before application code runs, blocking other connections served by the process. The cost grows with max_header_size, and only availability is affected. This issue is fixed in version 6.6.

CVSS Base Scores

version 3.1