Changelog

Python 3.10.19 final

Release date: 2025-10-09

Security

  • gh-139700: 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.

  • gh-139400: xml.parsers.expat: Make sure that parent Expat parsers are only garbage-collected once they are no longer referenced by subparsers created by ExternalEntityParserCreate(). Patch by Sebastian Pipping.

  • gh-135661: Fix parsing start and end tags in html.parser.HTMLParser according to the HTML5 standard.

    • Whitespaces no longer accepted between </ and the tag name. E.g. </ script> does not end the script section.

    • Vertical tabulation (\v) and non-ASCII whitespaces no longer recognized as whitespaces. The only whitespaces are \t\n\r\f and space.

    • Null character (U+0000) no longer ends the tag name.

    • Attributes and slashes after the tag name in end tags are now ignored, instead of terminating after the first > in quoted attribute value. E.g. </script/foo=">"/>.

    • Multiple slashes and whitespaces between the last attribute and closing > are now ignored in both start and end tags. E.g. <a foo=bar/ //>.

    • Multiple = between attribute name and value are no longer collapsed. E.g. <a foo==bar> produces attribute “foo” with value “=bar”.

  • gh-135661: Fix CDATA section parsing in html.parser.HTMLParser according to the HTML5 standard: ] ]> and ]] > no longer end the CDATA section. Add private method _set_support_cdata() which can be used to specify how to parse <[CDATA[ — as a CDATA section in foreign content (SVG or MathML) or as a bogus comment in the HTML namespace.

  • gh-102555: Fix comment parsing in html.parser.HTMLParser according to the HTML5 standard. --!> now ends the comment. -- > no longer ends the comment. Support abnormally ended empty comments <--> and <--->.

  • gh-135462: Fix quadratic complexity in processing specially crafted input in html.parser.HTMLParser. End-of-file errors are now handled according to the HTML5 specs – comments and declarations are automatically closed, tags are ignored.

  • gh-118350: Fix support of escapable raw text mode (elements “textarea” and “title”) in html.parser.HTMLParser.

  • gh-86155: html.parser.HTMLParser.close() no longer loses data when the <script> tag is not closed. Patch by Waylan Limberg.

Library

  • gh-139312: Upgrade bundled libexpat to 2.7.3

  • gh-138998: Update bundled libexpat to 2.7.2

  • gh-130577: tarfile now validates archives to ensure member offsets are non-negative. (Contributed by Alexander Enrique Urieles Nieto in gh-130577.)

  • gh-135374: Update the bundled copy of setuptools to 79.0.1.

Python 3.10.18 final

Release date: 2025-06-03

Security

  • gh-135034: Fixes multiple issues that allowed tarfile extraction filters (filter="data" and filter="tar") to be bypassed using crafted symlinks and hard links.

    Addresses CVE 2024-12718, CVE 2025-4138, CVE 2025-4330, and CVE 2025-4517.

  • gh-133767: Fix use-after-free in the “unicode-escape” decoder with a non-“strict” error handler.

  • gh-128840: Short-circuit the processing of long IPv6 addresses early in ipaddress to prevent excessive memory consumption and a minor denial-of-service.

Library

Python 3.10.17 final

Release date: 2025-04-08

Security

  • gh-131809: Update bundled libexpat to 2.7.1

  • gh-131261: Upgrade to libexpat 2.7.0

  • gh-105704: When using urllib.parse.urlsplit() and urllib.parse.urlparse() host parsing would not reject domain names containing square brackets ([ and ]). Square brackets are only valid for IPv6 and IPvFuture hosts according to RFC 3986 Section 3.2.2.

  • gh-121284: Fix bug in the folding of rfc2047 encoded-words when flattening an email message using a modern email policy. Previously when an encoded-word was too long for a line, it would be decoded, split across lines, and re-encoded. But commas and other special characters in the original text could be left unencoded and unquoted. This could theoretically be used to spoof header lines using a carefully constructed encoded-word if the resulting rendered email was transmitted or re-parsed.

  • gh-80222: Fix bug in the folding of quoted strings when flattening an email message using a modern email policy. Previously when a quoted string was folded so that it spanned more than one line, the surrounding quotes and internal escapes would be omitted. This could theoretically be used to spoof header lines using a carefully constructed quoted string if the resulting rendered email was transmitted or re-parsed.

  • gh-119511: Fix a potential denial of service in the imaplib module. When connecting to a malicious server, it could cause an arbitrary amount of memory to be allocated. On many systems this is harmless as unused virtual memory is only a mapping, but if this hit a virtual address size limit it could lead to a MemoryError or other process crash. On unusual systems or builds where all allocated memory is touched and backed by actual ram or storage it could’ve consumed resources doing so until similarly crashing.

Library

  • gh-127257: In ssl, system call failures that OpenSSL reports using ERR_LIB_SYS are now raised as OSError.

Documentation

  • gh-121277: Writers of CPython’s documentation can now use next as the version for the versionchanged, versionadded, deprecated directives.

Python 3.10.16 final

Release date: 2024-12-03

Tests

  • gh-125041: Re-enable skipped tests for zlib on the s390x architecture: only skip checks of the compressed bytes, which can be different between zlib’s software implementation and the hardware-accelerated implementation.

  • gh-109396: Fix test_socket.test_hmac_sha1() in FIPS mode. Use a longer key: FIPS mode requires at least of at least 112 bits. The previous key was only 32 bits. Patch by Victor Stinner.

Security

  • gh-126623: Upgrade libexpat to 2.6.4

  • gh-122792: Changed IPv4-mapped ipaddress.IPv6Address to consistently use the mapped IPv4 address value for deciding properties. Properties which have their behavior fixed are is_multicast, is_reserved, is_link_local, is_global, and is_unspecified.

Library

Python 3.10.15 final

Release date: 2024-09-07

Windows

  • gh-119690: Fixes data type confusion in audit events raised by _winapi.CreateFile and _winapi.CreateNamedPipe.

  • gh-116773: Fix instances of <_overlapped.Overlapped object at 0xXXX> still has pending operation at deallocation, the process may crash.

Tests

  • gh-112769: The tests now correctly compare zlib version when zlib.ZLIB_RUNTIME_VERSION contains non-integer suffixes. For example zlib-ng defines the version as 1.3.0.zlib-ng.

  • gh-117187: Fix XML tests for vanilla Expat <2.6.0.

  • gh-100454: Fix SSL tests CI for OpenSSL 3.1+

Security

  • gh-123678: Upgrade libexpat to 2.6.3

  • gh-121957: Fixed missing audit events around interactive use of Python, now also properly firing for python -i, as well as for python -m asyncio. The event in question is cpython.run_stdin.

  • gh-122133: Authenticate the socket connection for the socket.socketpair() fallback on platforms where AF_UNIX is not available like Windows.

    Patch by Gregory P. Smith <greg@krypto.org> and Seth Larson <seth@python.org>. Reported by Ellie <el@horse64.org>

  • gh-121285: Remove backtracking from tarfile header parsing for hdrcharset, PAX, and GNU sparse headers.

  • gh-118486: os.mkdir() on Windows now accepts mode of 0o700 to restrict the new directory to the current user. This fixes CVE-2024-4030 affecting tempfile.mkdtemp() in scenarios where the base temporary directory is more permissive than the default.

  • gh-116741: Update bundled libexpat to 2.6.2

Library

Core and Builtins

  • gh-112275: A deadlock involving pystate.c’s HEAD_LOCK in posixmodule.c at fork is now fixed. Patch by ChuBoning based on previous Python 3.12 fix by Victor Stinner.

Python 3.10.14 final

Release date: 2024-03-19

Security

Core and Builtins

  • gh-102388: Fix a bug where iso2022_jp_3 and iso2022_jp_2004 codecs read out of bounds

Library

  • gh-115197: urllib.request no longer resolves the hostname before checking it against the system’s proxy bypass list on macOS and Windows.

  • gh-115133: Fix tests for XMLPullParser with Expat 2.6.0.

  • gh-81194: Fix a crash in socket.if_indextoname() with specific value (UINT_MAX). Fix an integer overflow in socket.if_indextoname() on 64-bit non-Windows platforms.

  • gh-109858: Protect zipfile from “quoted-overlap” zipbomb. It now raises BadZipFile when try to read an entry that overlaps with other entry or central directory.

  • gh-91133: Fix a bug in tempfile.TemporaryDirectory cleanup, which now no longer dereferences symlinks when working around file system permission errors.

Documentation

  • gh-115399: Document CVE-2023-52425 of Expat <2.6.0 under “XML vulnerabilities”.

Windows

  • gh-111239: Update Windows builds to use zlib v1.3.1.

  • gh-109991: Windows builds now use OpenSSL 1.1.1w. Note that OpenSSL 1.1 has reached its end of life and no future fixes will be made, and this version of Python is no longer receiving maintenance fixes and will not be updated to OpenSSL 3.0.

Tools/Demos

  • gh-109991: Update GitHub CI workflows to use OpenSSL 3.0.11 and multissltests to use 1.1.1w, 3.0.11, and 3.1.3.

Python 3.10.13 final

Release date: 2023-08-24

Security

  • gh-108310: Fixed an issue where instances of ssl.SSLSocket were vulnerable to a bypass of the TLS handshake and included protections (like certificate verification) and treating sent unencrypted data as if it were post-handshake TLS encrypted data. Security issue reported as CVE-2023-40217 by Aapo Oksman. Patch by Gregory P. Smith.

Library

  • gh-107845: tarfile.data_filter() now takes the location of symlinks into account when determining their target, so it will no longer reject some valid tarballs with LinkOutsideDestinationError.

Tools/Demos

  • gh-107565: Update multissltests and GitHub CI workflows to use OpenSSL 1.1.1v, 3.0.10, and 3.1.2.

C API

Python 3.10.12 final

Release date: 2023-06-06

Security

  • gh-103142: The version of OpenSSL used in our binary builds has been upgraded to 1.1.1u to address several CVEs.

  • gh-99889: Fixed a security in flaw in uu.decode() that could allow for directory traversal based on the input if no out_file was specified.

  • gh-104049: Do not expose the local on-disk location in directory indexes produced by http.client.SimpleHTTPRequestHandler.

  • gh-102153: urllib.parse.urlsplit() now strips leading C0 control and space characters following the specification for URLs defined by WHATWG in response to CVE-2023-24329. Patch by Illia Volochii.

Library

Documentation

Build

  • gh-103262: Fixes Windows installer build to work with latest compilers.

Python 3.10.11 final

Release date: 2023-04-04

Security

Core and Builtins

  • gh-102416: Do not memoize incorrectly automatically generated loop rules in the parser. Patch by Pablo Galindo.

  • gh-102356: Fix a bug that caused a crash when deallocating deeply nested filter objects. Patch by Marta Gómez Macías.

  • gh-102397: Fix segfault from race condition in signal handling during garbage collection. Patch by Kumar Aditya.

  • gh-102126: Fix deadlock at shutdown when clearing thread states if any finalizer tries to acquire the runtime head lock. Patch by Kumar Aditya.

  • gh-102027: Fix SSE2 and SSE3 detection in _blake2 internal module. Patch by Max Bachmann.

  • gh-101967: Fix possible segfault in positional_only_passed_as_keyword function, when new list created.

  • gh-101765: Fix SystemError / segmentation fault in iter __reduce__ when internal access of builtins.__dict__ keys mutates the iter object.

Library

  • gh-102947: Improve traceback when dataclasses.fields() is called on a non-dataclass. Patch by Alex Waygood

  • gh-101979: Fix a bug where parentheses in the metavar argument to argparse.ArgumentParser.add_argument() were dropped. Patch by Yeojin Kim.

  • gh-102179: Fix os.dup2() error message for negative fds.

  • gh-101961: For the binary mode, fileinput.hookcompressed() doesn’t set the encoding value even if the value is None. Patch by Gihwan Kim.

  • gh-101936: The default value of fp becomes io.BytesIO if HTTPError is initialized without a designated fp parameter. Patch by Long Vo.

  • gh-101566: In zipfile, apply fix for extractall on the underlying zipfile after being wrapped in Path.

  • gh-101997: Upgrade pip wheel bundled with ensurepip (pip 23.0.1)

  • gh-101892: Callable iterators no longer raise SystemError when the callable object exhausts the iterator but forgets to either return a sentinel value or raise StopIteration.

  • gh-97786: Fix potential undefined behaviour in corner cases of floating-point-to-time conversions.

  • gh-101517: Fixed bug where bdb looks up the source line with linecache with a lineno=None, which causes it to fail with an unhandled exception.

  • gh-101673: Fix a pdb bug where ll clears the changes to local variables.

  • gh-96931: Fix incorrect results from ssl.SSLSocket.shared_ciphers()

  • gh-88233: Correctly preserve “extra” fields in zipfile regardless of their ordering relative to a zip64 “extra.”

  • gh-95495: When built against OpenSSL 3.0, the ssl module had a bug where it reported unauthenticated EOFs (i.e. without close_notify) as a clean TLS-level EOF. It now raises SSLEOFError, matching the behavior in previous versions of OpenSSL. The options attribute on SSLContext also no longer includes OP_IGNORE_UNEXPECTED_EOF by default. This option may be set to specify the previous OpenSSL 3.0 behavior.

  • gh-94440: Fix a concurrent.futures.process bug where ProcessPoolExecutor shutdown could hang after a future has been quickly submitted and canceled.

Documentation

Tests

  • gh-102980: Improve test coverage on pdb.

  • gh-102537: Adjust the error handling strategy in test_zoneinfo.TzPathTest.python_tzpath_context. Patch by Paul Ganssle.

  • gh-101377: Improved test_locale_calendar_formatweekday of calendar.

Build

  • gh-102711: Fix -Wstrict-prototypes compiler warnings.

Windows

  • gh-101759: Update Windows installer to SQLite 3.40.1.

  • gh-101614: Correctly handle extensions built against debug binaries that reference python3_d.dll.

macOS

  • gh-103207: Add instructions to the macOS installer welcome display on how to workaround the macOS 13 Ventura “The installer encountered an error” failure.

  • gh-101759: Update macOS installer to SQLite 3.40.1.

  • gh-87235: On macOS python3 /dev/fd/9 9</path/to/script.py failed for any script longer than a couple of bytes.

Python 3.10.10 final

Release date: 2023-02-07

Core and Builtins

  • gh-101400: Fix wrong lineno in exception message on continue or break which are not in a loop. Patch by Dong-hee Na.

  • gh-101372: Fix is_normalized() to properly handle the UCD 3.2.0 cases. Patch by Dong-hee Na.

  • gh-101046: Fix a possible memory leak in the parser when raising MemoryError. Patch by Pablo Galindo

  • gh-100942: Fixed segfault in property.getter/setter/deleter that occurred when a property subclass overrode the __new__ method to return a non-property instance.

  • gh-100892: Fix race while iterating over thread states in clearing threading.local. Patch by Kumar Aditya.

  • gh-100776: Fix misleading default value in input()’s __text_signature__.

  • gh-100374: Fix incorrect result and delay in socket.getfqdn(). Patch by Dominic Socular.

  • gh-100050: Honor existing errors obtained when searching for mismatching parentheses in the tokenizer. Patch by Pablo Galindo

  • bpo-32782: ctypes arrays of length 0 now report a correct itemsize when a memoryview is constructed from them, rather than always giving a value of 0.

Library

Documentation

Tests

  • gh-101334: test_tarfile has been updated to pass when run as a high UID.

  • gh-96002: Add functional test for Argument Clinic.

Build

  • gh-101522: Allow overriding Windows dependencies versions and paths using MSBuild properties.

Windows

  • gh-82052: Fixed an issue where writing more than 32K of Unicode output to the console screen in one go can result in mojibake.

  • gh-100180: Update Windows installer to OpenSSL 1.1.1s

  • bpo-43984: winreg.SetValueEx() now leaves the target value untouched in the case of conversion errors. Previously, -1 would be written in case of such errors.

macOS

  • gh-100180: Update macOS installer to OpenSSL 1.1.1s

C API

  • gh-99240: In argument parsing, after deallocating newly allocated memory, reset its pointer to NULL.

Python 3.10.9 final

Release date: 2022-12-06

Security

  • gh-100001: python -m http.server no longer allows terminal control characters sent within a garbage request to be printed to the stderr server log.

    This is done by changing the http.server BaseHTTPRequestHandler .log_message method to replace control characters with a \xHH hex escape before printing.

  • gh-87604: Avoid publishing list of active per-interpreter audit hooks via the gc module

  • gh-98433: The IDNA codec decoder used on DNS hostnames by socket or asyncio related name resolution functions no longer involves a quadratic algorithm. This prevents a potential CPU denial of service if an out-of-spec excessive length hostname involving bidirectional characters were decoded. Some protocols such as urllib http 3xx redirects potentially allow for an attacker to supply such a name.

  • gh-98739: Update bundled libexpat to 2.5.0

  • gh-98517: Port XKCP’s fix for the buffer overflows in SHA-3 (CVE-2022-37454).

  • gh-97514: On Linux the multiprocessing module returns to using filesystem backed unix domain sockets for communication with the forkserver process instead of the Linux abstract socket namespace. Only code that chooses to use the “forkserver” start method is affected.

    Abstract sockets have no permissions and could allow any user on the system in the same network namespace (often the whole system) to inject code into the multiprocessing forkserver process. This was a potential privilege escalation. Filesystem based socket permissions restrict this to the forkserver process user as was the default in Python 3.8 and earlier.

    This prevents Linux CVE-2022-42919.

Core and Builtins

  • gh-99578: Fix a reference bug in _imp.create_builtin() after the creation of the first sub-interpreter for modules builtins and sys. Patch by Victor Stinner.

  • gh-99581: Fixed a bug that was causing a buffer overflow if the tokenizer copies a line missing the newline caracter from a file that is as long as the available tokenizer buffer. Patch by Pablo galindo

  • gh-96055: Update faulthandler to emit an error message with the proper unexpected signal number. Patch by Dong-hee Na.

  • gh-98852: Fix subscription of types.GenericAlias instances containing bare generic types: for example tuple[A, T][int], where A is a generic type, and T is a type variable.

  • gh-98415: Fix detection of MAC addresses for uuid on certain OSs. Patch by Chaim Sanders

  • gh-92119: Print exception class name instead of its string representation when raising errors from ctypes calls.

  • gh-93696: Allow pdb to locate source for frozen modules in the standard library.

  • bpo-31718: Raise ValueError instead of SystemError when methods of uninitialized io.IncrementalNewlineDecoder objects are called. Patch by Oren Milman.

  • bpo-38031: Fix a possible assertion failure in io.FileIO when the opener returns an invalid file descriptor.

Library

  • gh-100001: Also escape s in the http.server BaseHTTPRequestHandler.log_message so that it is technically possible to parse the line and reconstruct what the original data was. Without this a xHH is ambiguious as to if it is a hex replacement we put in or the characters r”x” came through in the original request line.

  • gh-93453: asyncio.get_event_loop() now only emits a deprecation warning when a new event loop was created implicitly. It no longer emits a deprecation warning if the current event loop was set.

  • gh-51524: Fix bug when calling trace.CoverageResults with valid infile.

  • gh-99645: Fix a bug in handling class cleanups in unittest.TestCase. Now addClassCleanup() uses separate lists for different TestCase subclasses, and doClassCleanups() only cleans up the particular class.

  • gh-97001: Release the GIL when calling termios APIs to avoid blocking threads.

  • gh-99341: Fix ast.increment_lineno() to also cover ast.TypeIgnore when changing line numbers.

  • gh-74044: Fixed bug where inspect.signature() reported incorrect arguments for decorated methods.

  • gh-99275: Fix SystemError in ctypes when exception was not set during __initsubclass__.

  • gh-99155: Fix statistics.NormalDist pickle with 0 and 1 protocols.

  • gh-99134: Update the bundled copy of pip to version 22.3.1.

  • gh-99130: Apply bugfixes from importlib_metadata 4.11.4, namely: In PathDistribution._name_from_stem, avoid including parts of the extension in the result. In PathDistribution._normalized_name, ensure names loaded from the stem of the filename are also normalized, ensuring duplicate entry points by packages varying only by non-normalized name are hidden.

  • gh-83004: Clean up refleak on failed module initialisation in _zoneinfo

  • gh-83004: Clean up refleaks on failed module initialisation in in _pickle

  • gh-83004: Clean up refleak on failed module initialisation in _io.

  • gh-98897: Fix memory leak in math.dist() when both points don’t have the same dimension. Patch by Kumar Aditya.

  • gh-98793: Fix argument typechecks in _overlapped.WSAConnect() and _overlapped.Overlapped.WSASendTo() functions.

  • gh-98740: Fix internal error in the re module which in very rare circumstances prevented compilation of a regular expression containing a conditional expression without the “else” branch.

  • gh-98703: Fix asyncio.StreamWriter.drain() to call protocol.connection_lost callback only once on Windows.

  • gh-98624: Add a mutex to unittest.mock.NonCallableMock to protect concurrent access to mock attributes.

  • gh-89237: Fix hang on Windows in subprocess.wait_closed() in asyncio with ProactorEventLoop. Patch by Kumar Aditya.

  • gh-98458: Fix infinite loop in unittest when a self-referencing chained exception is raised

  • gh-97928: tkinter.Text.count() raises now an exception for options starting with “-” instead of silently ignoring them.

  • gh-97966: On uname_result, restored expectation that _fields and _asdict would include all six properties including processor.

  • gh-98331: Update the bundled copies of pip and setuptools to versions 22.3 and 65.5.0 respectively.

  • gh-96035: Fix bug in urllib.parse.urlparse() that causes certain port numbers containing whitespace, underscores, plus and minus signs, or non-ASCII digits to be incorrectly accepted.

  • gh-98251: Allow venv to pass along PYTHON* variables to ensurepip and pip when they do not impact path resolution

  • gh-98178: On macOS, fix a crash in syslog.syslog() in multi-threaded applications. On macOS, the libc syslog() function is not thread-safe, so syslog.syslog() no longer releases the GIL to call it. Patch by Victor Stinner.

  • gh-96151: Allow BUILTINS to be a valid field name for frozen dataclasses.

  • gh-98086: Make sure patch.dict() can be applied on async functions.

  • gh-88863: To avoid apparent memory leaks when asyncio.open_connection() raises, break reference cycles generated by local exception and future instances (which has exception instance as its member var). Patch by Dong Uk, Kang.

  • gh-93858: Prevent error when activating venv in nested fish instances.

  • bpo-46364: Restrict use of sockets instead of pipes for stdin of subprocesses created by asyncio to AIX platform only.

  • bpo-38523: shutil.copytree() now applies the ignore_dangling_symlinks argument recursively.

  • bpo-36267: Fix IndexError in argparse.ArgumentParser when a store_true action is given an explicit argument.

Documentation

  • gh-92892: Document that calling variadic functions with ctypes requires special care on macOS/arm64 (and possibly other platforms).

Tests

  • gh-99892: Skip test_normalization() of test_unicodedata if it fails to download NormalizationTest.txt file from pythontest.net. Patch by Victor Stinner.

  • bpo-34272: Some C API tests were moved into the new Lib/test/test_capi/ directory.

Build

  • gh-99086: Fix -Wimplicit-int, -Wstrict-prototypes, and -Wimplicit-function-declaration compiler warnings in configure checks.

  • gh-99086: Fix -Wimplicit-int compiler warning in configure check for PTHREAD_SCOPE_SYSTEM.

  • gh-97731: Specify the full path to the source location for make docclean (needed for cross-builds).

  • gh-98671: Fix NO_MISALIGNED_ACCESSES being not defined for the SHA3 extension when HAVE_ALIGNED_REQUIRED is set. Allowing builds on hardware that unaligned memory accesses are not allowed.

Windows

  • gh-99345: Use faster initialization functions to detect install location for Windows Store package

  • gh-98689: Update Windows builds to zlib v1.2.13. v1.2.12 has CVE-2022-37434, but the vulnerable inflateGetHeader API is not used by Python.

  • gh-94328: Update Windows installer to use SQLite 3.39.4.

  • bpo-40882: Fix a memory leak in multiprocessing.shared_memory.SharedMemory on Windows.

macOS

  • gh-94328: Update macOS installer to SQLite 3.39.4.

IDLE

  • gh-97527: Fix a bug in the previous bugfix that caused IDLE to not start when run with 3.10.8, 3.12.0a1, and at least Microsoft Python 3.10.2288.0 installed without the Lib/test package. 3.11.0 was never affected.

Tools/Demos

  • gh-95731: Fix handling of module docstrings in Tools/i18n/pygettext.py.

Python 3.10.8 final

Release date: 2022-10-11

Security

  • gh-97616: Fix multiplying a list by an integer (list *= int): detect the integer overflow when the new allocated length is close to the maximum size. Issue reported by Jordan Limor. Patch by Victor Stinner.

  • gh-97612: Fix a shell code injection vulnerability in the get-remote-certificate.py example script. The script no longer uses a shell to run openssl commands. Issue reported and initial fix by Caleb Shortt. Patch by Victor Stinner.

  • gh-68966: The deprecated mailcap module now refuses to inject unsafe text (filenames, MIME types, parameters) into shell commands. Instead of using such text, it will warn and act as if a match was not found (or for test commands, as if the test failed).

Core and Builtins

  • gh-96078: os.sched_yield() now release the GIL while calling sched_yield(2). Patch by Dong-hee Na.

  • gh-97943: Bugfix: PyFunction_GetAnnotations() should return a borrowed reference. It was returning a new reference.

  • gh-97591: Fixed a missing incref/decref pair in Exception.__setstate__(). Patch by Ofey Chan.

  • gh-96848: Fix command line parsing: reject -X int_max_str_digits option with no value (invalid) when the PYTHONINTMAXSTRDIGITS environment variable is set to a valid limit. Patch by Victor Stinner.

  • gh-95921: Fix overly-broad source position information for chained comparisons used as branching conditions.

  • gh-96821: Fix undefined behaviour in _testcapimodule.c.

  • gh-95778: When ValueError is raised if an integer is larger than the limit, mention the sys.set_int_max_str_digits() function in the error message. Patch by Victor Stinner.

  • gh-96387: At Python exit, sometimes a thread holding the GIL can wait forever for a thread (usually a daemon thread) which requested to drop the GIL, whereas the thread already exited. To fix the race condition, the thread which requested the GIL drop now resets its request before exiting. Issue discovered and analyzed by Mingliang ZHAO. Patch by Victor Stinner.

  • gh-96864: Fix a possible assertion failure, fatal error, or SystemError if a line tracing event raises an exception while opcode tracing is enabled.

  • gh-96678: Fix undefined behaviour in C code of null pointer arithmetic.

  • gh-96641: Do not expose KeyWrapper in _functools.

  • gh-96611: When loading a file with invalid UTF-8 inside a multi-line string, a correct SyntaxError is emitted.

  • gh-95196: Disable incorrect pickling of the C implemented classmethod descriptors.

  • gh-96352: Fix AttributeError missing name and obj attributes in object.__getattribute__(). Patch by Philip Georgi.

  • bpo-42316: Document some places where an assignment expression needs parentheses.

Library

  • gh-87730: Wrap network errors consistently in urllib FTP support, so the test suite doesn’t fail when a network is available but the public internet is not reachable.

  • gh-97825: Fixes AttributeError when subprocess.check_output() is used with argument input=None and either of the arguments encoding or errors are used.

  • gh-96827: Avoid spurious tracebacks from asyncio when default executor cleanup is delayed until after the event loop is closed (e.g. as the result of a keyboard interrupt).

  • gh-97592: Avoid a crash in the C version of asyncio.Future.remove_done_callback() when an evil argument is passed.

  • gh-97639: Remove tokenize.NL check from tabnanny.

  • gh-97545: Make Semaphore run faster.

  • gh-73588: Fix generation of the default name of tkinter.Checkbutton. Previously, checkbuttons in different parent widgets could have the same short name and share the same state if arguments “name” and “variable” are not specified. Now they are globally unique.

  • gh-97005: Update bundled libexpat to 2.4.9

  • gh-85760: Fix race condition in asyncio where process_exited() called before the pipe_data_received() leading to inconsistent output. Patch by Kumar Aditya.

  • gh-96819: Fixed check in multiprocessing.resource_tracker that guarantees that the length of a write to a pipe is not greater than PIPE_BUF.

  • gh-96741: Corrected type annotation for dataclass attribute pstats.FunctionProfile.ncalls to be str.

  • gh-96652: Fix the faulthandler implementation of faulthandler.register(signal, chain=True) if the sigaction() function is not available: don’t call the previous signal handler if it’s NULL. Patch by Victor Stinner.

  • gh-96073: In inspect, fix overeager replacement of “typing.” in formatting annotations.

  • gh-90467: Fix asyncio.streams.StreamReaderProtocol to keep a strong reference to the created task, so that it’s not garbage collected

  • gh-96052: Fix handling compiler warnings (SyntaxWarning and DeprecationWarning) in codeop.compile_command() when checking for incomplete input. Previously it emitted warnings and raised a SyntaxError. Now it always returns None for incomplete input without emitting any warnings.

  • gh-91212: Fixed flickering of the turtle window when the tracer is turned off. Patch by Shin-myoung-serp.

  • gh-74116: Allow asyncio.StreamWriter.drain() to be awaited concurrently by multiple tasks. Patch by Kumar Aditya.

  • gh-90155: Fix broken asyncio.Semaphore when acquire is cancelled.

  • gh-92986: Fix ast.unparse() when ImportFrom.level is None

  • gh-91539: Improve performance of urllib.request.getproxies_environment when there are many environment variables

Documentation

  • gh-97741: Fix ! in c domain ref target syntax via a conf.py patch, so it works as intended to disable ref target resolution.

  • gh-95588: Clarified the conflicting advice given in the ast documentation about