PERL5385DELTA(1)

💖 perl5385delta — what is new for perl v5.38.5 💖

okay bestie, welcome to PERL5385DELTA(1), the little glow-up diary for perl v5.38.5 🎀 pull up a chair, grab a strawberry, and let's get into it 💅

---

✨ NAME ✨

perl5385delta — what is new for perl v5.38.5 🦋

---

🌸 DESCRIPTION 🌸

This document describes the differences between the 5.38.4 release and the 5.38.5 release. it's giving "small but mighty patch notes" energy fr fr 💖

If you are upgrading from an earlier release such as 5.38.3, first read perl5384delta, which describes the differences between 5.38.3 and 5.38.4. don't skip it, i'm literally begging 🙈

---

🚨 Security 🚨

[CVE-2025-40909] Perl threads have a working directory race condition where file operations may target unintended paths

ngl this one is the main character of this whole release, and not in a cute way 😭

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. that's the fix, that's the whole vibe, periodt 💀

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/>. shoutout to them, icons only 👑

Fixes were provided via GH #23019 <https://github.com/Perl/perl5/pull/23019> and GH #23361 <https://github.com/Perl/perl5/pull/23361>. two PRs, one slay 💅

---

💜 Incompatible Changes 💜

There are no changes intentionally incompatible with 5.38.4. and if any exist? they are bugs, and we request that you submit a report. See "Reporting Bugs" below. no cap, we wanna know 🌈

---

🎀 Modules and Pragmata 🎀

Updated Modules and Pragmata

• Module::CoreList has been upgraded from version 5.20250413_38 to 5.20250803_38. glow up complete ✨

---

📚 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>. pls tell us, we're not mind readers (yet) 🫶

---

🧪 Testing 🧪

Tests were added and changed to reflect the other additions and changes in this release. test coverage said "i'm the moment" and she was right 💅

---

👑 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. the math is mathing, the effort is efforting 🔥

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. fourth decade?! she's been that girl since forever 👑

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. literal legends, every single one 💖

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. we see you and we love you 🙈

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. CPAN girlies, this one's for you 🌸

For a more complete list of all of Perl's historical contributors, please see the AUTHORS file in the Perl source distribution. it's a whole family tree and it's iconic 🌈

---

🐛 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. do a lil vibe check first bestie 💅

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. tiny but sufficient, that's the assignment fr fr ✨

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. do not just post it publicly, that's not the move 😭

---

🫶 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. go be sweet, it costs zero dollars and it absolutely makes someone's day 💌

---

🌟 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.

---

and that's the whole page babes 💖 this was perl v5.42.3, dated 2026-08-03, signing off with main character energy 👑 stay slaying, stay patched, and remember: no chdir, no problem ✨🎀🦋