.. date: 2025-11-12-12-54-28
.. gh-issue: 141442
.. nonce: 50dS3P
.. release date: 2025-12-02
.. section: Tools/Demos

The iOS testbed now correctly handles test arguments that contain spaces.

..

.. date: 2025-10-23-16-39-49
.. gh-issue: 140482
.. nonce: ZMtyeD
.. section: Tests

Preserve and restore the state of ``stty echo`` as part of the test
environment.

..

.. date: 2025-10-15-00-52-12
.. gh-issue: 140082
.. nonce: fpET50
.. section: Tests

Update ``python -m test`` to set ``FORCE_COLOR=1`` when being run with color
enabled so that :mod:`unittest` which is run by it with redirected output
will output in color.

..

.. date: 2025-07-09-21-45-51
.. gh-issue: 136442
.. nonce: jlbklP
.. section: Tests

Use exitcode ``1`` instead of ``5`` if :func:`unittest.TestCase.setUpClass`
raises an exception

..

.. date: 2025-10-07-19-31-34
.. gh-issue: 139700
.. nonce: vNHU1O
.. section: Security

Check consistency of the zip64 end of central directory record. Support
records with "zip64 extensible data" if there are no bytes prepended to the
ZIP file.

..

.. date: 2025-08-15-23-08-44
.. gh-issue: 137836
.. nonce: b55rhh
.. section: Security

Add support of the "plaintext" element, RAWTEXT elements "xmp", "iframe",
"noembed" and "noframes", and optionally RAWTEXT element "noscript" in
:class:`html.parser.HTMLParser`.

..

.. date: 2025-06-28-13-23-53
.. gh-issue: 136063
.. nonce: aGk0Jv
.. section: Security

:mod:`email.message`: ensure linear complexity for legacy HTTP parameters
parsing. Patch by Bénédikt Tran.

..

.. date: 2025-05-30-22-33-27
.. gh-issue: 136065
.. nonce: bu337o
.. section: Security

Fix quadratic complexity in :func:`os.path.expandvars`.

..

.. date: 2024-05-21-22-11-31
.. gh-issue: 119342
.. nonce: BTFj4Z
.. section: Security

Fix a potential memory denial of service in the :mod:`plistlib` module. When
reading a Plist file received from untrusted source, it could cause an
arbitrary amount of memory to be allocated. This could have led to symptoms
including a :exc:`MemoryError`, swapping, out of memory (OOM) killed
processes or containers, or even system crashes.

..

.. date: 2025-11-29-04-20-44
.. gh-issue: 74389
.. nonce: pW3URj
.. section: Library

When the stdin being used by a :class:`subprocess.Popen` instance is closed,
this is now ignored in :meth:`subprocess.Popen.communicate` instead of
leaving the class in an inconsistent state.

..

.. date: 2025-11-29-03-02-45
.. gh-issue: 87512
.. nonce: bn4xbm
.. section: Library

Fix :func:`subprocess.Popen.communicate` timeout handling on Windows when
writing large input. Previously, the timeout was ignored during stdin
writing, causing the method to block indefinitely if the child process did
not consume input quickly. The stdin write is now performed in a background
thread, allowing the timeout to be properly enforced.

..

.. date: 2025-11-27-20-16-38
.. gh-issue: 141473
.. nonce: Wq4xVN
.. section: Library

When :meth:`subprocess.Popen.communicate` was called with *input* and a
*timeout* and is called for a second time after a
:exc:`~subprocess.TimeoutExpired` exception before the process has died, it
should no longer hang.

..

.. date: 2025-11-25-16-00-29
.. gh-issue: 59000
.. nonce: YtOyJy
.. section: Library

Fix :mod:`pdb` breakpoint resolution for class methods when the module
defining the class is not imported.

..

.. date: 2025-11-18-14-39-31
.. gh-issue: 141570
.. nonce: q3n984
.. section: Library

Support :term:`file-like object` raising :exc:`OSError` from
:meth:`~io.IOBase.fileno` in color detection (``_colorize.can_colorize()``).
This can occur when ``sys.stdout`` is redirected.

..

.. date: 2025-11-17-08-16-30
.. gh-issue: 141659
.. nonce: QNi9Aj
.. section: Library

Fix bad file descriptor errors from ``_posixsubprocess`` on AIX.

..

.. date: 2025-11-14-16-24-20
.. gh-issue: 141497
.. nonce: L_CxDJ
.. section: Library

:mod:`ipaddress`: ensure that the methods :meth:`IPv4Network.hosts()
<ipaddress.IPv4Network.hosts>` and :meth:`IPv6Network.hosts()
<ipaddress.IPv6Network.hosts>` always return an iterator.

..

.. date: 2025-11-13-14-51-30
.. gh-issue: 140938
.. nonce: kXsHHv
.. section: Library

The :func:`statistics.stdev` and :func:`statistics.pstdev` functions now
raise a :exc:`ValueError` when the input contains an infinity or a NaN.

..

.. date: 2025-11-12-15-42-47
.. gh-issue: 124111
.. nonce: hTw4OE
.. section: Library

Updated Tcl threading configuration in :mod:`_tkinter` to assume that
threads are always available in Tcl 9 and later.

..

.. date: 2025-11-12-01-49-03
.. gh-issue: 137109
.. nonce: D6sq2B
.. section: Library

The :mod:`os.fork` and related forking APIs will no longer warn in the
common case where Linux or macOS platform APIs return the number of threads
in a process and find the answer to be 1 even when a
:func:`os.register_at_fork` ``after_in_parent=`` callback (re)starts a
thread.

..

.. date: 2025-11-10-01-47-18
.. gh-issue: 141314
.. nonce: baaa28
.. section: Library

Fix assertion failure in :meth:`io.TextIOWrapper.tell` when reading files
with standalone carriage return (``\r``) line endings.

..

.. date: 2025-11-09-18-55-13
.. gh-issue: 141311
.. nonce: qZ3swc
.. section: Library

Fix assertion failure in :func:`!io.BytesIO.readinto` and undefined behavior
arising when read position is above capcity in :class:`io.BytesIO`.

..

.. date: 2025-11-06-15-11-50
.. gh-issue: 141141
.. nonce: tgIfgH
.. section: Library

Fix a thread safety issue with :func:`base64.b85decode`. Contributed by
Benel Tayar.

..

.. date: 2025-11-03-17-13-00
.. gh-issue: 140911
.. nonce: 7KFvSQ
.. section: Library

:mod:`collections`: Ensure that the methods ``UserString.rindex()`` and
``UserString.index()`` accept :class:`collections.UserString` instances as
the sub argument.

..

.. date: 2025-11-03-16-23-54
.. gh-issue: 140797
.. nonce: DuFEeR
.. section: Library

The undocumented :class:`!re.Scanner` class now forbids regular expressions
containing capturing groups in its lexicon patterns. Patterns using
capturing groups could previously lead to crashes with segmentation fault.
Use non-capturing groups (?:...) instead.

..

.. date: 2025-11-02-19-23-32
.. gh-issue: 140815
.. nonce: McEG-T
.. section: Library

:mod:`faulthandler` now detects if a frame or a code object is invalid or
freed. Patch by Victor Stinner.

..

.. date: 2025-11-02-11-46-00
.. gh-issue: 100218
.. nonce: 9Ezfdq
.. section: Library

Correctly set :attr:`~OSError.errno` when :func:`socket.if_nametoindex` or
:func:`socket.if_indextoname` raise an :exc:`OSError`. Patch by Bénédikt
Tran.

..

.. date: 2025-11-02-10-44-23
.. gh-issue: 140875
.. nonce: wt6B37
.. section: Library

Fix handling of unclosed character references (named and numerical) followed
by the end of file in :class:`html.parser.HTMLParser` with
``convert_charrefs=False``.

..

.. date: 2025-11-02-09-37-22
.. gh-issue: 140734
.. nonce: f8gST9
.. section: Library

:mod:`multiprocessing`: fix off-by-one error when checking the length of a
temporary socket file path. Patch by Bénédikt Tran.

..

.. date: 2025-11-01-00-36-14
.. gh-issue: 140874
.. nonce: eAWt3K
.. section: Library

Bump the version of pip bundled in :mod:`ensurepip` to version 25.3

..

.. date: 2025-10-31-15-06-26
.. gh-issue: 140691
.. nonce: JzHGtg
.. section: Library

In :mod:`urllib.request`, when opening a FTP URL fails because a data
connection cannot be made, the control connection's socket is now closed to
avoid a :exc:`ResourceWarning`.

..

.. date: 2025-10-31-13-57-55
.. gh-issue: 103847
.. nonce: VM7TnW
.. section: Library

Fix hang when cancelling process created by
:func:`asyncio.create_subprocess_exec` or
:func:`asyncio.create_subprocess_shell`. Patch by Kumar Aditya.

..

.. date: 2025-10-27-18-29-42
.. gh-issue: 140590
.. nonce: LT9HHn
.. section: Library

Fix arguments checking for the :meth:`!functools.partial.__setstate__` that
may lead to internal state corruption and crash. Patch by Sergey Miryanov.

..

.. date: 2025-10-27-13-49-31
.. gh-issue: 140634
.. nonce: ULng9G
.. section: Library

Fix a reference counting bug in :meth:`!os.sched_param.__reduce__`.

..

.. date: 2025-10-26-16-24-12
.. gh-issue: 140633
.. nonce: ioayC1
.. section: Library

Ignore :exc:`AttributeError` when setting a module's ``__file__`` attribute
when loading an extension module packaged as Apple Framework.

..

.. date: 2025-10-25-21-26-16
.. gh-issue: 140593
.. nonce: OxlLc9
.. section: Library

:mod:`xml.parsers.expat`: Fix a memory leak that could affect users with
:meth:`~xml.parsers.expat.xmlparser.ElementDeclHandler` set to a custom
element declaration handler. Patch by Sebastian Pipping.

..

.. date: 2025-10-25-21-04-00
.. gh-issue: 140607
.. nonce: oOZGxS
.. section: Library

Inside :meth:`io.RawIOBase.read`, validate that the count of bytes returned
by :meth:`io.RawIOBase.readinto` is valid (inside the provided buffer).

..

.. date: 2025-10-23-19-39-16
.. gh-issue: 138162
.. nonce: Znw5DN
.. section: Library

Fix :class:`logging.LoggerAdapter` with ``merge_extra=True`` and without the
*extra* argument.

..

.. date: 2025-10-22-20-52-13
.. gh-issue: 140474
.. nonce: xIWlip
.. section: Library

Fix memory leak in :class:`array.array` when creating arrays from an empty
:class:`str` and the ``u`` type code.

..

.. date: 2025-10-17-23-58-11
.. gh-issue: 140272
.. nonce: lhY8uS
.. section: Library

Fix memory leak in the :meth:`!clear` method of the :mod:`dbm.gnu` database.

..

.. date: 2025-10-15-21-42-13
.. gh-issue: 140041
.. nonce: _Fka2j
.. section: Library

Fix import of :mod:`ctypes` on Android and Cygwin when ABI flags are
present.

..

.. date: 2025-10-11-10-02-56
.. gh-issue: 139905
.. nonce: UyJIR_
.. section: Library

Add suggestion to error message for :class:`typing.Generic` subclasses when
``cls.__parameters__`` is missing due to a parent class failing to call
:meth:`super().__init_subclass__() <object.__init_subclass__>` in its
``__init_subclass__``.

..

.. date: 2025-10-09-21-37-20
.. gh-issue: 139845
.. nonce: dzx5UP
.. section: Library

Fix to not print KeyboardInterrupt twice in default asyncio REPL.

..

.. date: 2025-10-09-13-48-28
.. gh-issue: 139783
.. nonce: __NUgo
.. section: Library

Fix :func:`inspect.getsourcelines` for the case when a decorator is followed
by a comment or an empty line.

..

.. date: 2025-10-02-17-40-10
.. gh-issue: 70765
.. nonce: zVlLZn
.. section: Library

:mod:`http.server`: fix default handling of HTTP/0.9 requests in
:class:`~http.server.BaseHTTPRequestHandler`. Previously,
:meth:`!BaseHTTPRequestHandler.parse_request` incorrectly waited for headers
in the request although those are not supported in HTTP/0.9. Patch by
Bénédikt Tran.

..

.. date: 2025-09-28-16-34-11
.. gh-issue: 139391
.. nonce: nRFnmx
.. section: Library

Fix an issue when, on non-Windows platforms, it was not possible to
gracefully exit a ``python -m asyncio`` process suspended by Ctrl+Z and
later resumed by :manpage:`fg` other than with :manpage:`kill`.

..

.. date: 2025-09-25-20-16-10
.. gh-issue: 101828
.. nonce: yTxJlJ
.. section: Library

Fix ``'shift_jisx0213'``, ``'shift_jis_2004'``, ``'euc_jisx0213'`` and
``'euc_jis_2004'`` codecs truncating null chars as they were treated as part
of multi-character sequences.

..

.. date: 2025-09-23-09-46-46
.. gh-issue: 139246
.. nonce: pzfM-w
.. section: Library

fix: paste zero-width in default repl width is wrong.

..

.. date: 2025-09-22-14-40-11
.. gh-issue: 90949
.. nonce: UM35nb
.. section: Library

Add :meth:`~xml.parsers.expat.xmlparser.SetAllocTrackerActivationThreshold`
and :meth:`~xml.parsers.expat.xmlparser.SetAllocTrackerMaximumAmplification`
to :ref:`xmlparser <xmlparser-objects>` objects to prevent use of
disproportional amounts of dynamic memory from within an Expat parser. Patch
by Bénédikt Tran.

..

.. date: 2025-09-17-19-08-34
.. gh-issue: 139065
.. nonce: Hu8fM5
.. section: Library

Fix trailing space before a wrapped long word if the line length is exactly
*width* in :mod:`textwrap`.

..

.. date: 2025-09-16-16-46-58
.. gh-issue: 138993
.. nonce: -8s8_T
.. section: Library

Dedent :data:`credits` text.

..

.. date: 2025-09-13-12-19-17
.. gh-issue: 138859
.. nonce: PxjIoN
.. section: Library

Fix generic type parameterization raising a :exc:`TypeError` when omitting a
:class:`ParamSpec` that has a default which is not a list of types.

..

.. date: 2025-09-11-15-03-37
.. gh-issue: 138775
.. nonce: w7rnSx
.. section: Library

Use of ``python -m`` with :mod:`base64` has been fixed to detect input from
a terminal so that it properly notices EOF.

..

.. date: 2025-09-03-20-18-39
.. gh-issue: 98896
.. nonce: tjez89
.. section: Library

Fix a failure in multiprocessing resource_tracker when SharedMemory names
contain colons. Patch by Rani Pinchuk.

..

.. date: 2025-08-01-23-52-49
.. gh-issue: 75989
.. nonce: 5aYXNJ
.. section: Library

:func:`tarfile.TarFile.extractall` and :func:`tarfile.TarFile.extract` now
overwrite symlinks when extracting hardlinks. (Contributed by Alexander
Enrique Urieles Nieto in :gh:`75989`.)

..

.. date: 2025-07-21-01-16-32
.. gh-issue: 83424
.. nonce: Y3tEV4
.. section: Library

Allows creating a :class:`ctypes.CDLL` without name when passing a handle as
an argument.

..

.. date: 2025-07-17-16-12-23
.. gh-issue: 136234
.. nonce: VmTxtj
.. section: Library

Fix :meth:`asyncio.WriteTransport.writelines` to be robust to connection
failure, by using the same behavior as
:meth:`~asyncio.WriteTransport.write`.

..

.. date: 2025-07-01-04-57-57
.. gh-issue: 136057
.. nonce: 4-t596
.. section: Library

Fixed the bug in :mod:`pdb` and :mod:`bdb` where ``next`` and ``step`` can't
go over the line if a loop exists in the line.

..

.. date: 2025-06-10-18-02-29
.. gh-issue: 135307
.. nonce: fXGrcK
.. section: Library

:mod:`email`: Fix exception in ``set_content()`` when encoding text and
max_line_length is set to ``0`` or ``None`` (unlimited).

..

.. date: 2025-05-30-18-37-44
.. gh-issue: 134453
.. nonce: kxkA-o
.. section: Library

Fixed :func:`subprocess.Popen.communicate` ``input=`` handling of
:class:`memoryview` instances that were non-byte shaped on POSIX platforms.
Those are now properly cast to a byte shaped view instead of truncating the
input.  Windows platforms did not have this bug.

..

.. date: 2023-03-21-10-59-40
.. gh-issue: 102431
.. nonce: eUDnf4
.. section: Library

Clarify constraints for "logical" arguments in methods of
:class:`decimal.Context`.

..

.. date: 2025-10-09-12-53-47
.. gh-issue: 96491
.. nonce: 4YKxvy
.. section: IDLE

Deduplicate version number in IDLE shell title bar after saving to a file.

..

.. date: 2025-11-26-23-30-09
.. gh-issue: 141994
.. nonce: arBEG6
.. section: Documentation

:mod:`xml.sax.handler`: Make Documentation of
:data:`xml.sax.handler.feature_external_ges` warn of opening up to `external
entity attacks <https://en.wikipedia.org/wiki/XML_external_entity_attack>`_.
Patch by Sebastian Pipping.

..

.. date: 2025-10-27-23-06-01
.. gh-issue: 140578
.. nonce: FMBdEn
.. section: Documentation

Remove outdated sencence in the documentation for :mod:`multiprocessing`,
that implied that :class:`concurrent.futures.ThreadPoolExecutor` did not
exist.

..

.. date: 2025-12-01-20-41-26
.. gh-issue: 142048
.. nonce: c2YosX
.. section: Core and Builtins

Fix quadratically increasing garbage collection delays in free-threaded
build.

..

.. date: 2025-11-24-21-09-30
.. gh-issue: 141930
.. nonce: hIIzSd
.. section: Core and Builtins

When importing a module, use Python's regular file object to ensure that
writes to ``.pyc`` files are complete or an appropriate error is raised.

..

.. date: 2025-11-22-10-43-26
.. gh-issue: 120158
.. nonce: 41_rXd
.. section: Core and Builtins

Fix inconsistent state when enabling or disabling monitoring events too many
times.

..

.. date: 2025-11-15-01-21-00
.. gh-issue: 141579
.. nonce: aB7cD9
.. section: Core and Builtins

Fix :func:`sys.activate_stack_trampoline` to properly support the
``perf_jit`` backend. Patch by Pablo Galindo.

..

.. date: 2025-11-10-23-07-06
.. gh-issue: 141312
.. nonce: H-58GB
.. section: Core and Builtins

Fix the assertion failure in the ``__setstate__`` method of the range
iterator when a non-integer argument is passed. Patch by Sergey Miryanov.

..

.. date: 2025-11-03-17-21-38
.. gh-issue: 140939
.. nonce: FVboAw
.. section: Core and Builtins

Fix memory leak when :class:`bytearray` or :class:`bytes` is formated with
the ``%*b`` format with a large width that results in a :exc:`MemoryError`.

..

.. date: 2025-11-02-12-47-38
.. gh-issue: 140530
.. nonce: S934bp
.. section: Core and Builtins

Fix a reference leak when ``raise exc from cause`` fails. Patch by Bénédikt
Tran.

..

.. date: 2025-10-25-17-36-46
.. gh-issue: 140576
.. nonce: kj0SCY
.. section: Core and Builtins

Fixed crash in :func:`tokenize.generate_tokens` in case of specific
incorrect input. Patch by Mikhail Efimov.

..

.. date: 2025-10-24-20-42-33
.. gh-issue: 140551
.. nonce: -9swrl
.. section: Core and Builtins

Fixed crash in :class:`dict` if :meth:`dict.clear` is called at the lookup
stage. Patch by Mikhail Efimov and Inada Naoki.

..

.. date: 2025-10-23-16-05-50
.. gh-issue: 140471
.. nonce: Ax_aXn
.. section: Core and Builtins

Fix potential buffer overflow in :class:`ast.AST` node initialization when
encountering malformed :attr:`~ast.AST._fields` containing non-:class:`str`.

..

.. date: 2025-10-21-06-51-50
.. gh-issue: 140406
.. nonce: 0gJs8M
.. section: Core and Builtins

Fix memory leak when an object's :meth:`~object.__hash__` method returns an
object that isn't an :class:`int`.

..

.. date: 2025-10-18-21-29-45
.. gh-issue: 140306
.. nonce: xS5CcS
.. section: Core and Builtins

Fix memory leaks in cross-interpreter channel operations and shared
namespace handling.

..

.. date: 2025-10-18-18-08-36
.. gh-issue: 140301
.. nonce: m-2HxC
.. section: Core and Builtins

Fix memory leak of ``PyConfig`` in subinterpreters.

..

.. date: 2025-10-13-17-56-23
.. gh-issue: 140000
.. nonce: tLhn3e
.. section: Core and Builtins

Fix potential memory leak when a reference cycle exists between an instance
of :class:`typing.TypeAliasType`, :class:`typing.TypeVar`,
:class:`typing.ParamSpec`, or :class:`typing.TypeVarTuple` and its
``__name__`` attribute. Patch by Mikhail Efimov.

..

.. date: 2025-10-08-13-52-00
.. gh-issue: 139748
.. nonce: jq0yFJ
.. section: Core and Builtins

Fix reference leaks in error branches of functions accepting path strings or
bytes such as :func:`compile` and :func:`os.system`. Patch by Bénédikt Tran.

..

.. date: 2025-10-06-13-15-26
.. gh-issue: 139516
.. nonce: d9Pkur
.. section: Core and Builtins

Fix lambda colon erroneously start format spec in f-string in tokenizer.

..

.. date: 2025-10-06-10-03-37
.. gh-issue: 139640
.. nonce: gY5oTb
.. section: Core and Builtins

Fix swallowing some syntax warnings in different modules if they
accidentally have the same message and are emitted from the same line. Fix
duplicated warnings in the ``finally`` block.

..

.. date: 2025-08-07-09-52-19
.. gh-issue: 137400
.. nonce: AK1dy-
.. section: Core and Builtins

Fix a crash in the :term:`free threading` build when disabling profiling or
tracing across all threads with :c:func:`PyEval_SetProfileAllThreads` or
:c:func:`PyEval_SetTraceAllThreads` or their Python equivalents
:func:`threading.settrace_all_threads` and
:func:`threading.setprofile_all_threads`.

..

.. date: 2025-05-11-09-40-19
.. gh-issue: 133400
.. nonce: zkWla8
.. section: Core and Builtins

Fixed Ctrl+D (^D) behavior in _pyrepl module to match old pre-3.13 REPL
behavior.

..

.. date: 2025-11-18-04-16-09
.. gh-issue: 140042
.. nonce: S1C7id
.. section: C API

Removed the sqlite3_shutdown call that could cause closing connections for
sqlite when used with multiple sub interpreters.

..

.. date: 2025-10-26-16-45-06
.. gh-issue: 140487
.. nonce: fGOqss
.. section: C API

Fix :c:macro:`Py_RETURN_NOTIMPLEMENTED` in limited C API 3.11 and older:
don't treat ``Py_NotImplemented`` as immortal. Patch by Victor Stinner.
