The vulnerability of the _parseparam function in the httputil.py component of the Python Tornado web framework, which allows a hacker to cause a denial-of-service attack.

The vulnerability of the parseparam function in the httputil.py component of the Python Tornado web framework involves an uncontrolled resource consumption. Exploiting this vulnerability could allow a malicious actor to cause service failures...

tornado: Tornado Quadratic DoS via Crafted Multipart Parameters

A denial of service flaw has been discovered in the Tornado networking library. Affected versions of Tornado us an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The parseparam function in httputil.py is used to parse specific HTTP header values,...

OESA-2025-2881 python-tornado security update

Tornado is an open source version of the scalable, non-blocking web server and tools. Security Fixes: Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a...

Excessive Iteration

Overview tornado is a Python web framework and asynchronous networking library, originally developed at FriendFeed. Affected versions of this package are vulnerable to Excessive Iteration in the parseparam function. An attacker can cause the server to become unresponsive and consume excessive CPU...

PT-2025-50888

Name of the Vulnerable Software and Affected Versions Tornado versions 6.5.2 and below Description Tornado, a Python web framework and asynchronous networking library, is susceptible to a denial-of-service DoS condition. The parseparam function within the httputil.py file utilizes an inefficient...