PERL5381DELTA(1)

🦋 NAME 🦋

perl5381delta — what is new for perl v5.38.1 💖

---

🌸 DESCRIPTION 🌸

okay so bestie, this whole document is the tea on what changed between the 5.38.0 release and the 5.38.1 release. two versions, one little glow-up. ✨

and if you're upgrading from something even earlier — like, say, 5.36.0 — you gotta read perl5380delta first. that one describes the differences between 5.36.0 and 5.38.0. it's giving prerequisite reading, no skipping. 📚

🔒 Security 🔒

this release fixes the following security issues. and these are the real deal, so like, eyes on the screen please. 👀

🚨 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".

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's a memory-safety oopsie in the regex engine. patch it, bestie, for real.

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

this one 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.

so basically, Perl for Windows relies on the system path environment variable to find the shell ("cmd.exe"). when you run an executable which uses the Windows Perl interpreter, Perl attempts to find and execute "cmd.exe" within the operating system. but — plot twist — due to path search order issues, Perl initially looks for cmd.exe in the current working directory. 🙈

and 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. 💀

not me... it's a privilege escalation. yes it's that serious.

---

💐 Acknowledgements 💐

Perl 5.38.1 represents approximately 5 months of development since Perl 5.38.0, and it contains approximately 6,100 lines of changes across 34 files from 4 authors. that's a whole semester of work, fr fr. 🔥

and excluding auto-generated files, documentation and release tools, there were approximately 1,300 lines of changes to 9 .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 5.38.1:

• 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. 🫶

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. tiny! but sufficient! that's the assignment. 💅

if the bug you're 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. go be sweet about it, it costs literally nothing. 💖

---

👀 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, bestie! 🎀 this was perl5381delta from the Perl Programmers Reference Guide, running on perl v5.42.3, dated 2026-08-03. slay, now go patch your perl. 👑💅