PERL5343DELTA(1)

💖 PERL5343DELTA 💖

okay bestie, welcome to the tea on perl5343delta — it's the page that spills what's new in perl v5.34.3, and it lives in the Perl Programmers Reference Guide (yes, that's the manual name, consider it folded in like a cute lil bookmark 🎀). grab a snack, this one's mostly a security glow-up but we're doing it together, fr fr.

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✨ NAME ✨

perl5343delta — what is new for perl v5.34.3 🦋

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🌸 DESCRIPTION 🌸

So this doc is the receipts on the differences between the 5.34.1 release and the 5.34.3 release. 💅

real talk: this document ignores Perl 5.34.2, which was a broken release that only existed for a couple of days. not me pretending it never happened 😭 it just literally was not it. we move.

If you're upgrading from something even older like 5.34.0, you gotta read perl5341delta first, because that one covers the differences between 5.34.0 and 5.34.1. no skipping steps, bestie, the lore matters 📚✨

🔒 Security 🔒

This release fixes the following security issues. two of them. both slay in the "closing a hole" way, not the fun way. 🫶

🚨 CVE-2023-47038 - Write past buffer end via illegal user-defined Unicode property

This vulnerability was reported directly to the Perl security team by Nathan Mills the.true.nathan.mills@gmail.com. (yes, that's his email, character for character, we respect the reporter 💜)

Here's the vibe: a crafted regular expression, when compiled by perl 5.30.0 through 5.38.0, can cause a one-byte attacker controlled buffer overflow in a heap allocated buffer. 😭 that is so not the move. patched now. periodt.

🚨 CVE-2023-47039 - Perl for Windows binary hijacking vulnerability

This vulnerability was reported to the Intel Product Security Incident Response Team (PSIRT) by GitHub user ycdxsb https://github.com/ycdxsb/WindowsPrivilegeEscalation. PSIRT then reported it to the Perl security team. teamwork honestly 👑

So here's the whole situation: Perl for Windows relies on the system path environment variable to find the shell (cmd.exe). When running an executable which uses Windows Perl interpreter, Perl attempts to find and execute cmd.exe within the operating system. However, due to path search order issues, Perl initially looks for cmd.exe in the current working directory. 🙈

An attacker with limited privileges can exploit this behavior by placing cmd.exe in locations with weak permissions, such as C:\ProgramData. By doing so, when an administrator attempts to use this executable from these compromised locations, arbitrary code can be executed. 💀 that's the whole scam. be careful out there, and also maybe don't have weak permissions, just a thought.

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💐 Acknowledgements 💐

Perl 5.34.3 represents approximately 1 month of development since Perl 5.34.1 and contains approximately 3,700 lines of changes across 40 files from 4 authors. iconic efficiency tbh ⭐

Excluding auto-generated files, documentation and release tools, there were approximately 2,800 lines of changes to 9 .pm, .t, .c and .h files. look at those extensions go 💅

Perl continues to flourish into its fourth decade thanks to a vibrant community of users and developers. and the following people are known to have contributed the improvements that became Perl 5.34.3:

• Karl Williamson
• Paul Evans
• Steve Hay
• Tony Cook

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. so if you reported something and you're not on here, you are still seen and loved, no cap 🫶

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.

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🐛 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. (tiny but sufficient. that's the energy. don't send us your whole codebase, bestie, we're begging 😭)

⚠️ 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, okay? that's the one thing. 🙏

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🫶 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 on, they deserve it, it's free and it's cute.

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👀 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.

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and that's the whole page, bestie 💖 this was perl v5.42.3, dated 2026-08-03 — yes, that's the version and date straight off the footer, folded into this lil sign-off instead of being copy-pasted at the bottom like a boring manpage would do. mwah, go patch your perl, ily 🎀🦋✨