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perl-5.27.3
River stage five • 12010 direct dependents • 33600 total dependents
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Security Advisories (8)
CVE-2020-12723 (2020-06-05)

regcomp.c in Perl before 5.30.3 allows a buffer overflow via a crafted regular expression because of recursive S_study_chunk calls.

CVE-2020-10878 (2020-06-05)

Perl before 5.30.3 has an integer overflow related to mishandling of a "PL_regkind[OP(n)] == NOTHING" situation. A crafted regular expression could lead to malformed bytecode with a possibility of instruction injection.

CVE-2020-10543 (2020-06-05)

Perl before 5.30.3 on 32-bit platforms allows a heap-based buffer overflow because nested regular expression quantifiers have an integer overflow.

CVE-2018-6798 (2018-04-17)

An issue was discovered in Perl 5.22 through 5.26. Matching a crafted locale dependent regular expression can cause a heap-based buffer over-read and potentially information disclosure.

CVE-2023-47039 (2023-10-30)

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.

CVE-2023-47100

In Perl before 5.38.2, S_parse_uniprop_string in regcomp.c can write to unallocated space because a property name associated with a \p{...} regular expression construct is mishandled. The earliest affected version is 5.30.0.

CVE-2024-56406 (2025-04-13)

A heap buffer overflow vulnerability was discovered in Perl. When there are non-ASCII bytes in the left-hand-side of the `tr` operator, `S_do_trans_invmap` can overflow the destination pointer `d`.    $ perl -e '$_ = "\x{FF}" x 1000000; tr/\xFF/\x{100}/;'    Segmentation fault (core dumped) It is believed that this vulnerability can enable Denial of Service and possibly Code Execution attacks on platforms that lack sufficient defenses.

CVE-2025-40909 (2025-05-30)

Perl threads have a working directory race condition where file operations may target unintended paths. If a directory handle is open at thread creation, the process-wide current working directory is temporarily changed in order to clone that handle for the new thread, which is visible from any third (or more) thread already running. This may lead to unintended operations such as loading code or accessing files from unexpected locations, which a local attacker may be able to exploit. The bug was introduced in commit 11a11ecf4bea72b17d250cfb43c897be1341861e and released in Perl version 5.13.6

NAME

perldelta - what is new for perl v5.27.3

DESCRIPTION

This document describes differences between the 5.27.2 release and the 5.27.3 release.

If you are upgrading from an earlier release such as 5.27.1, first read perl5272delta, which describes differences between 5.27.1 and 5.27.2.

Deprecations

Module removals

The following modules will be removed from the core distribution in a future release, and will at that time need to be installed from CPAN. Distributions on CPAN which require these modules will need to list them as prerequisites.

The core versions of these modules will now issue "deprecated"-category warnings to alert you to this fact. To silence these deprecation warnings, install the modules in question from CPAN.

Note that these are (with rare exceptions) fine modules that you are encouraged to continue to use. Their disinclusion from core primarily hinges on their necessity to bootstrapping a fully functional, CPAN-capable Perl installation, not usually on concerns over their design.

B::Debug

Performance Enhancements

  • SvTRUE() is now more efficient.

  • keys() in void and scalar contexts is now more efficient.

  • Various integer-returning ops are now more efficient in scalar/boolean context.

  • if (index(...) != -1) { ... } is now more efficient.

  • for() loops and similar constructs are now more efficient in most cases.

Modules and Pragmata

Updated Modules and Pragmata

  • B has been upgraded from version 1.68 to 1.69.

  • B::Concise has been upgraded from version 1.000 to 1.001.

  • B::Debug has been upgraded from version 1.24 to 1.25. NOTE: B::Debug is deprecated and may be removed from a future version of Perl.

  • B::Deparse has been upgraded from version 1.41 to 1.42.

  • base has been upgraded from version 2.25 to 2.26.

  • Data::Dumper has been upgraded from version 2.167 to 2.167_02.

  • Devel::Peek has been upgraded from version 1.26 to 1.27.

  • ExtUtils::Constant has been upgraded from version 0.23 to 0.24.

  • ExtUtils::ParseXS has been upgraded from version 3.34 to 3.35.

  • ExtUtils::Typemaps has been upgraded from version 3.34 to 3.35.

  • Filter::Simple has been upgraded from version 0.93 to 0.94.

  • Module::CoreList has been upgraded from version 5.20170720 to 5.20170821.

  • SelfLoader has been upgraded from version 1.23 to 1.24.

  • Storable has been upgraded from version 2.63 to 2.64.

  • threads has been upgraded from version 2.16 to 2.17.

  • utf8 has been upgraded from version 1.19 to 1.20.

Configuration and Compilation

  • On GCC, -Werror=pointer-arith is now enabled by default, disallowing arithmetic on void and function pointers.

Selected Bug Fixes

  • Fixed a duplicate symbol failure with -flto -mieee-fp builds. pp.c defined _LIB_VERSION which -lieee already defines. [perl #131786]

  • The tokenizer no longer consumes the exponent part of a floating point number if it's incomplete. [perl #131725]

  • On non-threaded builds, for m/$null/ where $null is an empty string is no longer treated as if the /o flag was present when the previous matching match operator included the /o flag. The rewriting used to implement this behavior could confuse the interpreter. This matches the behaviour of threaded builds. [perl #124368]

Acknowledgements

Perl 5.27.3 represents approximately 5 weeks of development since Perl 5.27.2 and contains approximately 5,600 lines of changes across 150 files from 19 authors.

Excluding auto-generated files, documentation and release tools, there were approximately 4,000 lines of changes to 84 .pm, .t, .c and .h files.

Perl continues to flourish into its third decade thanks to a vibrant community of users and developers. The following people are known to have contributed the improvements that became Perl 5.27.3:

Aaron Crane, Aristotle Pagaltzis, Chris 'BinGOs' Williams, Craig A. Berry, Dagfinn Ilmari Mannsåker, Daniel Dragan, David Mitchell, Father Chrysostomos, James E Keenan, Karl Williamson, Ken Brown, Lukas Mai, Matthew Horsfall, Nicholas Clark, Robin Barker, Steffen Müller, Steve Hay, Tony Cook, Zefram.

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://rt.perl.org/ . There may also be information at http://www.perl.org/ , the Perl Home Page.

If you believe you have an unreported bug, please run the perlbug program included with your release. Be sure to trim your bug down to a tiny but sufficient test case. Your bug report, along with the output of perl -V, will be sent off to perlbug@perl.org to be analysed by the Perl porting team.

If the bug you are reporting has security implications which make it inappropriate to send to a publicly archived mailing list, 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.