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-21737369
  • published27 Oct 2026
  • disclosed26 Oct 2026

Introduced: 26 Oct 2026

NewCVE-2026-115927  (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 6.6.0, Tornado decodes HTTP/1.1 chunked transfer encoding by processing body data that has already arrived without yielding to the event loop. A remote unauthenticated peer can send millions of one-byte chunks to monopolize the process event loop and stall every other connection served by that process, while lowering max_body_size only limits the duration of each request. For handlers that do not use @stream_request_body, retaining each chunk as a separate object can consume roughly twenty times the received body size, and SimpleAsyncHTTPClient has the same event-loop behavior when reading a response from a malicious server. This issue is fixed in version 6.6.0.

CVSS Base Scores

version 3.1