Converting between :class:`int` and :class:`str` in bases other than 2
(binary), 4, 8 (octal), 16 (hexadecimal), or 32 such as base 10 (decimal) now
raises a :exc:`ValueError` if the number of digits in string form is above a
limit to avoid potential denial of service attacks due to the algorithmic
complexity. This is a mitigation for `CVE-2020-10735
<https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-10735>`_.

This new limit can be configured or disabled by environment variable, command
line flag, or :mod:`sys` APIs. See the :ref:`integer string conversion length
limitation <int_max_str_digits>` documentation.  The default limit is 4300
digits in string form.

Patch by Gregory P. Smith [Google] and Christian Heimes [Red Hat] with feedback
from Victor Stinner, Thomas Wouters, Steve Dower, and Ned Deily.