Tuesday, February 17, 2026

Join the Python Security Response Team!

 Thanks to the work of the Security Developer-in-Residence Seth Larson, the Python Security Response Team (PSRT) now has an approved public governance document (PEP 811). Following the new governance structure the PSRT now publishes a public list of members, has documented responsibilities for members and admins, and a defined process for onboarding and offboarding members to balance the needs of security and sustainability. The document also clarifies the relationship between the Python Steering Council and the PSRT.

And this new onboarding process is already working! The PSF Infrastructure Engineer, Jacob Coffee, has just joined the PSRT as the first new non-"Release Manager" member since Seth joined the PSRT in 2023. We expect new members to join further bolstering the sustainability of security work for the Python programming language.

Thanks to Alpha-Omega for their support of Python ecosystem security by sponsoring Seth’s work as the Security Developer-in-Residence at the Python Software Foundation.

What is the Python Security Response Team?

Security doesn't happen by accident: it's thanks to the work of volunteers and paid Python Software Foundation staff on the Python Security Response Team to triage and coordinate vulnerability reports and remediations keeping all Python users safe. Just last year the PSRT published 16 vulnerability advisories for CPython and pip, the most in a single year to date!

And the PSRT usually can’t do this work alone, PSRT coordinators are encouraged to involve maintainers and experts on the projects and submodules. By involving the experts directly in the remediation process ensures fixes adhere to existing API conventions and threat-models, are maintainable long-term, and have minimal impact on existing use-cases.

Sometimes the PSRT even coordinates with other open source projects to avoid catching the Python ecosystem off-guard by publishing a vulnerability advisory that affects multiple other projects. The most recent example of this is PyPI’s ZIP archive differential attack mitigation.

This work deserves recognition and celebration just like contributions to source code and documentation. Seth and Jacob are developing further improvements to workflows involving “GitHub Security Advisories” to record the reporter, coordinator, and remediation developers and reviewers to CVE and OSV records to properly thank everyone involved in the otherwise private contribution to open source projects.

How can I join the Python Security Response Team?

Maybe you’ve read all this and are interested in directly helping the Python programming language be more secure! The process is similar to the Core Team nomination process, you need an existing PSRT member to nominate you and for your nomination to receive at least ⅔ positive votes from existing PSRT members.

You do not need to be a core developer, team member, or triager to be a member of the Python Security Response Team. Anyone with security expertise that is known and highly-trusted within the Python community and has time to volunteer or donate through their employer would make a good candidate for the PSRT. Please note that all PSRT team members have documented responsibilities and are expected to contribute meaningfully to the remediation of vulnerabilities.

Being a member of the PSRT is not required to be notified of vulnerabilities and shouldn’t be to receive “early notification” of vulnerabilities affecting CPython and pip. The Python Software Foundation is a CVE Numbering Authority and publishes CVE and OSV records with up-to-date information about vulnerabilities affecting CPython and pip.

Wednesday, February 11, 2026

Python 3.15.0 alpha 6

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a6/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a6, is the sixth of eight planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

  • PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
  • PEP 798: Unpacking in comprehensions with * and **
  • PEP 686: Python now uses UTF-8 as the default encoding
  • PEP 782: A new PyBytesWriter C API to create a Python bytes object
  • PEP 728: TypedDict with typed extra items
  • The JIT compiler has been significantly upgraded, with 3-4% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 7-8% speedup on AArch64 macOS over the tail-calling interpreter
  • Improved error messages
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.15 will be 3.15.0a7, currently scheduled for 2026-03-10.

More resources

And now for something completely different

By reason of these things, then, the whaling voyage was welcome; the great flood-gates of the wonder-world swung open, and in the wild conceits that swayed me to my purpose, two and two there floated into my inmost soul, endless processions of the whale, and, mid most of them all, one grand hooded phantom, like a snow hill in the air.

Enjoy the new release

Thanks to all of the many volunteers who help make Python development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Regards as the snow slowly falls in Helsinki,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

Tuesday, February 3, 2026

Python 3.14.3 and 3.13.12 are now available!

 Python 3.14.3 is now available!

This is third maintenance release of Python 3.14

Python 3.14.3 is the third maintenance release of 3.14, containing around 299 bugfixes, build improvements and documentation changes since 3.14.2.

https://www.python.org/downloads/release/python-3143/


Major new features of the 3.14 series, compared to 3.13

Some of the major new features and changes in Python 3.14 are:

New features

For more details on the changes to Python 3.14, see What’s new in Python 3.14.

Build changes

Incompatible changes, removals and new deprecations

Python install manager

The installer we offer for Windows is being replaced by our new install manager, which can be installed from the Windows Store or from its download page. See our documentation for more information. The JSON file available for download contains the list of all the installable packages available as part of this release, including file URLs and hashes, but is not required to install the latest release. The traditional installer will remain available throughout the 3.14 and 3.15 releases.

More resources

And now for something almost, but not quite, completely different

Python 3.13.12 is also now available!

https://www.python.org/downloads/release/python-31312/


This is the twelfth maintenance release of Python 3.13

Python 3.13.12 is the twelfth maintenance release of 3.13, containing around 250 bugfixes, build improvements and documentation changes since 3.13.11.

Enjoy the new releases

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Regards from an international releasing task force spread out over a whopping 10 timezones this time,

Your release team,
Thomas Wouters 
Hugo van Kemenade 
Ned Deily 
Steve Dower 
Łukasz Langa 

Wednesday, January 14, 2026

Python 3.15.0 alpha 5 (yes, another alpha!)

Note: 3.15.0a4 was accidentally built against main from 2025-12-23 instead of 2026-01-13, so this 3.15.0a5 is an extra release correctly built against 2026-01-14.

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a5/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a5, is the fifth of seven eight planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

  • PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
  • PEP 686: Python now uses UTF-8 as the default encoding
  • PEP 782: A new PyBytesWriter C API to create a Python bytes object
  • The JIT compiler has been significantly upgraded, with 4-5% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 7-8% speedup on AArch64 macOS over the tail-calling interpreter
  • Improved error messages
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.15 will be 3.15.0a6, currently scheduled for 2026-02-10.

More resources

And now for something completely different

At last it was given out that some time next day the ship would certainly sail. So next morning, Queequeg and I took a very early start.

Enjoy the new release

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Regards from a still snowfully subzero Helsinki,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

Tuesday, January 13, 2026

Python 3.15.0 alpha 4

Edit: This 3.15.0a4 was accidentally built against `main` from 2025-12-23 instead of 2026-01-13, so 3.15.0a5 is an extra release correctly built against 2026-01-14.

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a4/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a4, is the fourth of seven planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

  • PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
  • PEP 686: Python now uses UTF-8 as the default encoding
  • PEP 782: A new PyBytesWriter C API to create a Python bytes object
  • The JIT compiler has been significantly upgraded, with 3-4% geometric mean performance improvement on x86-64 Linux over the standard interpreter, and 7-8% speedup on AArch64 macOS over the tail-calling interpreter
  • Improved error messages
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.15 will be 3.15.0a5, currently scheduled for 2026-02-10.

More resources

And now for something completely different

Upon this every soul was confounded; for the phenomenon just then observed by Ahab had unaccountably escaped every one else; but its very blinding palpableness must have been the cause.

Thrusting his head half way into the binnacle, Ahab caught one glimpse of the compasses; his uplifted arm slowly fell; for a moment he almost seemed to stagger. Standing behind him Starbuck looked, and lo! the two compasses pointed East, and the Pequod was as infallibly going West.

But ere the first wild alarm could get out abroad among the crew, the old man with a rigid laugh exclaimed, “I have it! It has happened before. Mr. Starbuck, last night’s thunder turned our compasses—that’s all. Thou hast before now heard of such a thing, I take it.”

“Aye; but never before has it happened to me, sir,” said the pale mate, gloomily.

Enjoy the new release

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Regards from a snowfully subzero Helsinki,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

Tuesday, December 16, 2025

Python 3.15.0 alpha 3

This is an early developer preview of Python 3.15

www.python.org/downloads/release/python-3150a3/

Major new features of the 3.15 series, compared to 3.14

Python 3.15 is still in development. This release, 3.15.0a3, is the third of seven planned alpha releases.

Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process.

During the alpha phase, features may be added up until the start of the beta phase (2026-05-05) and, if necessary, may be modified or deleted up until the release candidate phase (2026-07-28). Please keep in mind that this is a preview release and its use is not recommended for production environments.

Many new features for Python 3.15 are still being planned and written. Among the new major new features and changes so far:

  • PEP 799: A new high-frequency, low-overhead, statistical sampling profiler and dedicated profiling package
  • PEP 686: Python now uses UTF-8 as the default encoding
  • PEP 782: A new PyBytesWriter C API to create a Python bytes object
  • Improved error messages
  • (Hey, fellow core developer, if a feature you find important is missing from this list, let Hugo know.)

The next pre-release of Python 3.15 will be 3.15.0a4, currently scheduled for 2026-01-13.

More resources

And now for something completely different

Instantly the captain ran forward, and in a loud voice commanded his crew to desist from hoisting the cutting-tackles, and at once cast loose the cables and chains confining the whales to the ship.

“What now?” said the Guernsey-man, when the Captain had returned to them.

“Why, let me see; yes, you may as well tell him now that—that—in fact, tell him I’ve diddled him, and (aside to himself) perhaps somebody else.”

Enjoy the new release

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Regards from an even deeper darker Helsinki,

Your release team,
Hugo van Kemenade
Ned Deily
Steve Dower
Łukasz Langa

Friday, December 5, 2025

Python 3.14.2 and 3.13.11 are now available!

Two more, just three days after the last? Yes!

We found some regressions, so here’s an expedited pair of releases. They also come with some bonus security fixes.

Python 3.14.2

www.python.org/downloads/release/python-3142/

Python 3.14.2 is the second maintenance release of 3.14, containing 18 bugfixes, build improvements and documentation changes since 3.14.1.

This is an expedited release to fix the following regressions:

  • gh-142206: Exceptions in multiprocessing in running programs while upgrading Python.

  • gh-142214: Exceptions in dataclasses without __init__ method.

  • gh-142218: Segmentation faults and assertion failures in insertdict.

  • gh-140797: Crash when using multiple capturing groups in re.Scanner

And these security fixes:

  • gh-142145: Remove quadratic behavior in node ID cache clearing (CVE-2025-12084)

  • gh-119452: Fix a potential virtual memory allocation denial of service in http.server

See the full changelog.

Python 3.13.11

www.python.org/downloads/release/python-31311/

Python 3.13.11 is the eleventh maintenance release of 3.13. This is an expedited release to fix the following regressions:

  • gh-142206: Exceptions in multiprocessing in running programs while upgrading Python.

  • gh-142218: Segmentation faults and assertion failures in insertdict.

  • gh-140797: Crash when using multiple capturing groups in re.Scanner

And these security fixes:

  • gh-142145: Remove quadratic behavior in node ID cache clearing (CVE-2025-12084)

  • gh-119451: Fix a potential denial of service in http.client

  • gh-119452: Fix a potential virtual memory allocation denial of service in http.server

See the full changelog.

Enjoy the new release

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organisation contributions to the Python Software Foundation.

Regards from deeper darker Helsinki,

Your release team,
Hugo van Kemenade
Thomas Wouters
Ned Deily
Steve Dower
Łukasz Langa