Issues

• LeakSanitizer reports leaked code object during SQLAlchemy editable build on 3.15 and main

  pendingtype-bug
  python/cpython#158963 · Filter by author ashm-dev opened on Oct 7, 2026
  1

• PyREPL corrupts attribute completion input on WSL/Windows Terminal

  OS-windowsstdlibtopic-repltype-bug
  python/cpython#158955 · Filter by author svankan opened on Oct 7, 2026

• _pyio.BytesIO.readinto() advances the stream when passed a read-only buffer

  stdlibtopic-IOtype-bug
  python/cpython#158952 · Filter by author emerardd opened on Oct 7, 2026

• Rework Modules/getbuildinfo.c to build strings at build time, instead of runtime

  interpreter-coretype-refactor
  python/cpython#158948 · Filter by author vstinner opened on Oct 7, 2026

• Py_MIN(), Py_MAX() and Py_ABS() cause C compatibility regressions

  3.16buildinterpreter-coretopic-C-APItype-bug
  python/cpython#158942 · Filter by author lpyu001 opened on Oct 6, 2026
  3

• Dataclass initialization inconsistently raises an error if a lazily imported annotation cannot be reified

  stdlibtopic-dataclassestopic-lazy-importstype-bug
  python/cpython#158936 · Filter by author brittanyrey opened on Oct 6, 2026

• Specialisation fail LOAD_ATTR_INSTANCE_VALUE specialised when no instance variable

  interpreter-coreperformancetype-bug
  python/cpython#158934 · Filter by author johng opened on Oct 6, 2026

• test_multiprocessing_spawn leaked a temporary file (tmpx_v21ney) on FreeBSD 16

  OS-freebsdteststopic-multiprocessing
  python/cpython#158933 · Filter by author vstinner opened on Oct 6, 2026
  2

• Optimize UTF-8 decoding to UCS1

  interpreter-coreperformancetype-feature
  python/cpython#158931 · Filter by author nineteendo opened on Oct 6, 2026
  2

• syslog cross-interpreter refcount race on static S_ident_o

  extension-modulestopic-subinterpreterstype-crash
  python/cpython#158929 · Filter by author error-3317 opened on Oct 6, 2026

• bytearray.__init__ slow-path append ignores ob_start leading to linear heap OOB write

  3.143.15interpreter-coretype-crash
  python/cpython#158928 · Filter by author error-3317 opened on Oct 6, 2026
  

• _PyUnicode_EncodeUTF16 backward error-handler under-reserve leading to heap overflow

  interpreter-coretype-crash
  python/cpython#158925 · Filter by author error-3317 opened on Oct 6, 2026

• _interpreters xibufferview_getbuf missing INCREF: shared-memoryview UAF

  3.143.153.16extension-modulestopic-subinterpreterstype-crash
  python/cpython#158923 · Filter by author error-3317 opened on Oct 6, 2026

• Excessive stack use in _PyModule_IsPossiblyShadowing

  interpreter-coretype-bug
  python/cpython#158918 · Filter by author Yhg1s opened on Oct 6, 2026
  

• "open" audit event "mode" does not contain information for os.open calls

  extension-modulestype-bug
  python/cpython#158916 · Filter by author johnkw opened on Oct 6, 2026
  6

• Direct HTTP 407 can receive HTTPS-scoped credentials

  3.113.123.133.143.153.16stdlibtype-security
  python/cpython#158907 · Filter by author bupt-Yy-young opened on Oct 6, 2026

• Race condition leads to AttributeError from BaseEventLoop.__del__

  pendingstdlibtopic-asynciotype-bug
  python/cpython#158903 · Filter by author bmerry opened on Oct 6, 2026
  5

• Potential async-signal-safety issue in asyncio.Runner._on_sigint

  stdlibtopic-asynciotype-bug
  python/cpython#158902 · Filter by author bmerry opened on Oct 6, 2026

• Free-threading scalability issue: contended PyMutex collapses with a few tens of threads (fair handoff)

  performancetopic-free-threading
  python/cpython#158901 · Filter by author cakedev0 opened on Oct 6, 2026
  1

• Optimize dict insertion and deletion by avoiding a second probe

  interpreter-coreperformancetype-feature
  python/cpython#158898 · Filter by author hetaozdh opened on Oct 6, 2026

• Performance regression in BufferedReader.readline() after switching to PyBytesWriter

  extension-modulesperformance
  python/cpython#158897 · Filter by author leandrodamascena opened on Oct 6, 2026
  5

• Improve regrtest integration with Github UI for test failures

  infrateststype-feature
  python/cpython#158895 · Filter by author cmaloney opened on Oct 6, 2026
  

• test_codecs: LocaleCodecTest fails with some locales on FreeBSD if UTF-8 Mode is disabled

  teststopic-unicode
  python/cpython#158890 · Filter by author vstinner opened on Oct 6, 2026

• Unlimited loop on trying to import the module of the filesystem encoding if iconv() is used

  teststopic-unicode
  python/cpython#158889 · Filter by author vstinner opened on Oct 6, 2026
  4

• test_codecs: IconvTest.test_encode_shift_state_flush() does crash on FreeBSD15

  OS-freebsdteststopic-unicode
  python/cpython#158888 · Filter by author vstinner opened on Oct 6, 2026
  1