=encoding utf8

=head1 NAME

perl5403delta - what is new for perl v5.40.3

=head1 DESCRIPTION

This document describes differences between the 5.40.2 release and the 5.40.3
release.

If you are upgrading from an earlier release such as 5.40.1, first read
L<perl5402delta>, which describes differences between 5.40.1 and 5.40.2.

=head1 Security

=head2 [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 5.40 will no longer chdir to each
handle.

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

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

=head1 Incompatible Changes

There are no changes intentionally incompatible with 5.40.2.  If any exist,
they are bugs, and we request that you submit a report.  See L</Reporting
Bugs> below.

=head1 Modules and Pragmata

=head2 Updated Modules and Pragmata

=over 4

=item *

L<Module::CoreList> has been upgraded from version 5.20250413_40 to 5.20250803_40.

=back

=head1 Documentation

=head2 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
L<https://github.com/Perl/perl5/issues>.

=head1 Testing

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

=head1 Acknowledgements

Perl 5.40.3 represents approximately 4 months of development since Perl 5.40.2
and contains approximately 3,400 lines of changes across 43 files from 7
authors.

Excluding auto-generated files, documentation and release tools, there were
approximately 1,100 lines of changes to 6 .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 5.40.3:

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 F<AUTHORS> file in the Perl source distribution.

=head1 Reporting Bugs

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

If you believe you have an unreported bug, please open an issue at
L<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
L<perlsec/SECURITY VULNERABILITY CONTACT INFORMATION> for details of how to
report the issue.

=head1 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 C<perlthanks> program:

    perlthanks

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

=head1 SEE ALSO

The F<Changes> file for an explanation of how to view exhaustive details on
what changed.

The F<INSTALL> file for how to build Perl.

The F<README> file for general stuff.

The F<Artistic> and F<Copying> files for copyright information.

=cut
