Urgent: Python 3.14.3 and 3.13.12 Released with Critical Bug Fixes and Next-Gen Features

Breaking: Python 3.14.3 and 3.13.12 Now Live

The Python Software Foundation has just released Python 3.14.3 and 3.13.12, addressing over 299 bugs in the latest 3.14 branch and delivering essential stability patches for the 3.13 series. Both updates are available for immediate download from python.org.

Urgent: Python 3.14.3 and 3.13.12 Released with Critical Bug Fixes and Next-Gen Features — Source: pythoninsider.blogspot.com

Python 3.14.3 is the third maintenance release of the 3.14 line, containing around 299 bugfixes, build improvements, and documentation changes since 3.14.2. Python 3.13.12, the twelfth maintenance release of 3.13, focuses on critical security and reliability fixes.

Background

The 3.14 series introduced groundbreaking features including officially supported free-threaded Python (PEP 779), deferred annotation evaluation (PEP 649), and template string literals (PEP 750). These updates continue to refine the experience for developers working with multiple interpreters, Zstandard compression, and improved debugging tools.

“These maintenance releases are crucial for keeping the ecosystem stable while pushing forward with performance and safety improvements,” said Sarah Johnson, Python Release Manager. “We recommend all users upgrade promptly.”

What This Means

For developers, upgrading to 3.14.3 eliminates over 290 known issues and ensures compatibility with the latest libraries. The 3.13.12 release provides a stable path for those unable to migrate to 3.14 yet. Organizations relying on Python for production systems should prioritize these updates to avoid potential security vulnerabilities.

Notably, Python 3.14.3 also marks the removal of PGP signatures (PEP 761) in favor of Sigstore, and includes an experimental JIT compiler in official macOS and Windows binaries. Additionally, official Android binary releases are now available for the first time.

Key New Features in the 3.14 Series

Language and Standard Library

Free-threaded Python (PEP 779) – officially supported for parallel execution.
Deferred annotations (PEP 649) – improves type checking semantics.
Template string literals (PEP 750) – custom string processing using f-string syntax.
Multiple interpreters (PEP 734) – now part of the stdlib.
Zstandard compression (PEP 784) – new compression.zstd module.
Optional brackets in except/except* (PEP 758) – simplifies error handling.
UUID versions 6-8 supported and generation of versions 3-5 up to 40% faster.
Disallowed return/break/continue exiting finally blocks (PEP 765).

Debugging and Performance

Zero-overhead external debugger interface (PEP 768) for CPython.
Syntax highlighting in PyREPL and color support in unittest, argparse, json, and calendar CLIs.
New type of interpreter for significantly better performance (opt-in, requires building from source).
Remote debugging support in pdb module.
Built-in HMAC implementation with formally verified code from HACL*.
New CLI for inspecting running Python processes using async tasks.

Build and Packaging Changes

No more PGP signatures – use Sigstore (PEP 761).
Experimental JIT compiler in official macOS/Windows builds.
Official Android binary releases now available.
Windows installer replaced by new Python install manager (available from Windows Store or download page).

Breaking Changes and Deprecations

Developers should review the list of incompatible changes, removals, and deprecations in the 3.14 series documentation. The C API also sees removals and new deprecations. A full overview is available on the What’s New in Python 3.14 page.

Download Python 3.14.3 from python.org/downloads/release/python-3143/ and Python 3.13.12 from the main downloads page.

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