PERLDELTA(1)

NAME
perldelta - what is new for perl v5.38.5

DESCRIPTION
This document describes differences between the 5.38.4 release and the 5.38.5 release.

If you are upgrading from an earlier release such as 5.38.3, first read perl5384delta, which describes differences between 5.38.3 and 5.38.4.

Security

  [CVE-2025-40909] Perl threads have a working directory race condition where file operations may target unintended paths
Perl thread cloning had a working directory race condition where file operations may target unintended paths. Perl 5.38 will no longer chdir to each handle.

This problem was discovered by Vincent Lefèvre via [GH #23010 <https://github.com/Perl/perl5/issues/23010>] and assigned [CVE-2025-40909 <https://lists.security.metacpan.org/cve-announce/msg/30017499/>] by the CPAN Security Group <https://security.metacpan.org/>.

Fixes were provided via [GH #23019 <https://github.com/Perl/perl5/pull/23019>] and [GH #23361 <https://github.com/Perl/perl5/pull/23361>].

Incompatible Changes
There are no changes intentionally incompatible with 5.38.4. If any exist, they are bugs, and we request that you submit a report. See "Reporting Bugs" below.

Modules and Pragmata

  Updated Modules and Pragmata

•   Module::CoreList has been upgraded from version 5.20250413_38 to 5.20250803_38.

Documentation

  Changes to Existing Documentation
We have attempted to update the documentation to reflect the changes listed in this document. If you find any we have missed, open an issue at <https://github.com/Perl/perl5/issues>.

Testing
Tests were added and changed to reflect the other additions and changes in this release.

Acknowledgements
Perl 5.38.5 represents approximately 4 months of development since Perl 5.38.4 and contains approximately 3,300 lines of changes across 46 files from 8 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 1,100 lines of changes to 7 .pm, .t, .c and .h files.

Perl continues to flourish into its fourth decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.38.5:

James E Keenan, Karen Etheridge, Leon Timmermans, Lukas Mai, Philippe Bruhat (BooK), Richard Leach, Steve Hay, Thibault Duponchelle.

The list above is almost certainly incomplete as it is automatically generated from version control history. In particular, it does not include the names of the (very much appreciated) contributors who reported issues to the Perl bug tracker.

Many of the changes included in this version originated in the CPAN modules included in Perl's core. We're grateful to the entire CPAN community for helping Perl to flourish.

For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution.

Reporting Bugs
If you find what you think is a bug, you might check the perl bug database at <https://github.com/Perl/perl5/issues>. There may also be information at <http://www.perl.org/>, the Perl Home Page.

If you believe you have an unreported bug, please open an issue at <https://github.com/Perl/perl5/issues>. Be sure to trim your bug down to a tiny but sufficient test case.

If the bug you are reporting has security implications which make it inappropriate to send to a public issue tracker, then see "SECURITY VULNERABILITY CONTACT INFORMATION" in perlsec for details of how to report the issue.

Give Thanks
If you wish to thank the Perl 5 Porters for the work we had done in Perl 5, you can do so by running the "perlthanks" program:

    perlthanks

This will send an email to the Perl 5 Porters list with your show of thanks.

SEE ALSO
The Changes file for an explanation of how to view exhaustive details on what changed.

The INSTALL file for how to build Perl.

The README file for general stuff.

The Artistic and Copying files for copyright information.