/ 
perl-5.27.7
⭐ Starred 2013
/ perlexperiment
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-2023-47100

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

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.

NAME

perlexperiment - A listing of experimental features in Perl

DESCRIPTION

This document lists the current and past experimental features in the perl core. Although all of these are documented with their appropriate topics, this succinct listing gives you an overview and basic facts about their status.

So far we've merely tried to find and list the experimental features and infer their inception, versions, etc. There's a lot of speculation here.

Current experiments

Smart match (~~) and switch (given/when)

Introduced in Perl 5.10.0

Modified in Perl 5.10.1, 5.12.0, 5.28.0

Using this feature triggers warnings in the category experimental::smartmatch.

The ticket for this feature is [perl #119317].

For historical reasons, the single experiment covers both the smart match operator (~~) and the switch-related compound statements (given/whereis/whereso).

Pluggable keywords

The ticket for this feature is [perl #119455].

See "PL_keyword_plugin" in perlapi for the mechanism.

Introduced in Perl 5.11.2

Regular Expression Set Operations

Introduced in Perl 5.18

The ticket for this feature is [perl #119451].

See also: "Extended Bracketed Character Classes" in perlrecharclass

Using this feature triggers warnings in the category experimental::regex_sets.

Subroutine signatures

Introduced in Perl 5.20.0

Using this feature triggers warnings in the category experimental::signatures.

The ticket for this feature is [perl #121481].

Aliasing via reference

Introduced in Perl 5.22.0

Using this feature triggers warnings in the category experimental::refaliasing.

The ticket for this feature is [perl #122947].

See also: "Assigning to References" in perlref

The "const" attribute

Introduced in Perl 5.22.0

Using this feature triggers warnings in the category experimental::const_attr.

The ticket for this feature is [perl #123630].

See also: "Constant Functions" in perlsub

use re 'strict';

Introduced in Perl 5.22.0

Using this feature triggers warnings in the category experimental::re_strict.

See "'strict' mode" in re

String- and number-specific bitwise operators

Introduced in Perl 5.22.0

See also: "Bitwise String Operators" in perlop

Using this feature triggers warnings in the category experimental::bitwise.

The ticket for this feature is [perl #123707].

The <:win32> IO pseudolayer

The ticket for this feature is [perl #119453].

See also perlrun

Declaring a reference to a variable

Introduced in Perl 5.26.0

Using this feature triggers warnings in the category experimental::declared_refs.

The ticket for this feature is [perl #128654].

See also: "Declaring a Reference to a Variable" in perlref

There is an installhtml target in the Makefile.

The ticket for this feature is [perl #116487].

Unicode in Perl on EBCDIC

Accepted features

These features were so wildly successful and played so well with others that we decided to remove their experimental status and admit them as full, stable features in the world of Perl, lavishing all the benefits and luxuries thereof. They are also awarded +5 Stability and +3 Charisma.

64-bit support

Introduced in Perl 5.005

die accepts a reference

Introduced in Perl 5.005

DB module

Introduced in Perl 5.6.0

See also perldebug, perldebtut

Weak references

Introduced in Perl 5.6.0

Internal file glob

Introduced in Perl 5.6.0

fork() emulation

Introduced in Perl 5.6.1

See also perlfork

-Dusemultiplicity -Duseithreads

Introduced in Perl 5.6.0

Accepted in Perl 5.8.0

Support for long doubles

Introduced in Perl 5.6.0

Accepted in Perl 5.8.1

The \N regex character class

The \N character class, not to be confused with the named character sequence \N{NAME}, denotes any non-newline character in a regular expression.

Introduced in Perl 5.12

Exact version of acceptance unclear, but no later than Perl 5.18.

(?{code}) and (??{ code })

Introduced in Perl 5.6.0

Accepted in Perl 5.20.0

See also perlre

Linux abstract Unix domain sockets

Introduced in Perl 5.9.2

Accepted before Perl 5.20.0. The Socket library is now primarily maintained on CPAN, rather than in the perl core.

See also Socket

Lvalue subroutines

Introduced in Perl 5.6.0

Accepted in Perl 5.20.0

See also perlsub

Backtracking control verbs

(*ACCEPT)

Introduced in Perl 5.10

Accepted in Perl 5.20.0

The <:pop> IO pseudolayer

See also perlrun

Accepted in Perl 5.20.0

\s in regexp matches vertical tab

Accepted in Perl 5.22.0

Postfix dereference syntax

Introduced in Perl 5.20.0

Accepted in Perl 5.24.0

Lexical subroutines

Introduced in Perl 5.18.0

Accepted in Perl 5.26.0

Removed features

These features are no longer considered experimental and their functionality has disappeared. It's your own fault if you wrote production programs using these features after we explicitly told you not to (see perlpolicy).

5.005-style threading

Introduced in Perl 5.005

Removed in Perl 5.10

perlcc

Introduced in Perl 5.005

Moved from Perl 5.9.0 to CPAN

The pseudo-hash data type

Introduced in Perl 5.6.0

Removed in Perl 5.9.0

GetOpt::Long Options can now take multiple values at once (experimental)

Getopt::Long upgraded to version 2.35

Removed in Perl 5.8.8

Assertions

The -A command line switch

Introduced in Perl 5.9.0

Removed in Perl 5.9.5

Test::Harness::Straps

Moved from Perl 5.10.1 to CPAN

legacy

The experimental legacy pragma was swallowed by the feature pragma.

Introduced in Perl 5.11.2

Removed in Perl 5.11.3

Lexical $_

Using this feature triggered warnings in the category experimental::lexical_topic.

Introduced in Perl 5.10.0

Removed in Perl 5.24.0

Array and hash container functions accept references

Using this feature triggered warnings in the category experimental::autoderef.

Superseded by "Postfix dereference syntax".

Introduced in Perl 5.14.0

Removed in Perl 5.24.0

our can have an experimental optional attribute unique

Introduced in Perl 5.8.0

Deprecated in Perl 5.10.0

Removed in Perl 5.28.0

SEE ALSO

For a complete list of features check feature.

AUTHORS

brian d foy <brian.d.foy@gmail.com>

Sébastien Aperghis-Tramoni <saper@cpan.org>

COPYRIGHT

Copyright 2010, brian d foy <brian.d.foy@gmail.com>

LICENSE

You can use and redistribute this document under the same terms as Perl itself.