/ 
perl-5.19.9
⭐ Starred 2013 / perlexperiment
Security Advisories (23)
CVE-2018-18314 (2018-12-07)

Perl before 5.26.3 has a buffer overflow via a crafted regular expression that triggers invalid write operations.

CVE-2016-2381 (2016-04-08)

Perl might allow context-dependent attackers to bypass the taint protection mechanism in a child process via duplicate environment variables in envp.

CVE-2013-7422 (2015-08-16)

Integer underflow in regcomp.c in Perl before 5.20, as used in Apple OS X before 10.10.5 and other products, allows context-dependent attackers to execute arbitrary code or cause a denial of service (application crash) via a long digit string associated with an invalid backreference within a regular expression.

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-2026-4176 (2026-03-29)

Perl versions from 5.9.4 before 5.40.4-RC1, from 5.41.0 before 5.42.2-RC1, from 5.43.0 before 5.43.9 contain a vulnerable version of Compress::Raw::Zlib. Compress::Raw::Zlib is included in the Perl package as a dual-life core module, and is vulnerable to CVE-2026-3381 due to a vendored version of zlib which has several vulnerabilities, including CVE-2026-27171. The bundled Compress::Raw::Zlib was updated to version 2.221 in Perl blead commit c75ae9cc164205e1b6d6dbd57bd2c65c8593fe94.

CVE-2026-57432 (2026-07-13)

Perl versions through 5.43.10 have an integer overflow in S_measure_struct leading to an out-of-bounds heap read in pack and unpack. S_measure_struct adds each item's size times its repeat count to a running total with no overflow check, so a large repeat count in a pack or unpack template wraps the signed SSize_t total negative. The @, X, and x position codes then guard their moves with a signed length comparison that passes when the length is negative, advancing the buffer pointer out of bounds. A template derived from untrusted input can read heap memory past the buffer and return it to the caller.

CVE-2026-8376 (2026-05-25)

Perl versions through 5.43.10 have a heap buffer overflow when compiling regular expressions with a repeated fixed string on 32-bit builds. Perl_study_chunk in regcomp_study.c checked the size of the joined substring buffer in characters rather than bytes. For a quantified fixed substring with a large minimum count, the byte length mincount * l could overflow SSize_t, producing an undersized SvGROW allocation; the subsequent copy writes past the end of the buffer. A caller that compiles an attacker-controlled regular expression on a 32-bit perl build triggers a heap buffer overflow at compile time.

CVE-2016-1238 (2016-08-02)

(1) cpan/Archive-Tar/bin/ptar, (2) cpan/Archive-Tar/bin/ptardiff, (3) cpan/Archive-Tar/bin/ptargrep, (4) cpan/CPAN/scripts/cpan, (5) cpan/Digest-SHA/shasum, (6) cpan/Encode/bin/enc2xs, (7) cpan/Encode/bin/encguess, (8) cpan/Encode/bin/piconv, (9) cpan/Encode/bin/ucmlint, (10) cpan/Encode/bin/unidump, (11) cpan/ExtUtils-MakeMaker/bin/instmodsh, (12) cpan/IO-Compress/bin/zipdetails, (13) cpan/JSON-PP/bin/json_pp, (14) cpan/Test-Harness/bin/prove, (15) dist/ExtUtils-ParseXS/lib/ExtUtils/xsubpp, (16) dist/Module-CoreList/corelist, (17) ext/Pod-Html/bin/pod2html, (18) utils/c2ph.PL, (19) utils/h2ph.PL, (20) utils/h2xs.PL, (21) utils/libnetcfg.PL, (22) utils/perlbug.PL, (23) utils/perldoc.PL, (24) utils/perlivp.PL, and (25) utils/splain.PL in Perl 5.x before 5.22.3-RC2 and 5.24 before 5.24.1-RC2 do not properly remove . (period) characters from the end of the includes directory array, which might allow local users to gain privileges via a Trojan horse module under the current working directory.

CVE-2026-15534 (2026-08-09)

Perl versions through 5.45.1 have out-of-bounds heap reads and writes during regular expression matching via an undersized superlinear cache in S_regmatch. The regex engine's superlinear cache holds one bit per subject position for each participating WHILEM node, so the bit count is the subject length plus one times the number of nodes. Nothing checks that product for positive overflow of the signed 32-bit count: a 286331153 byte subject matched against a pattern with 15 participating nodes stores the count as 14, leaving a two byte cache. The cache is then indexed from the real match position and node number, so reads go past the end of the allocation, and on failure CACHEsayNO sets a bit past it. A caller that matches an attacker controlled subject of this size against a pattern of this shape can crash the process or corrupt heap memory.

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-2026-13221 (2026-07-13)

Perl versions through 5.43.9 produce silently incorrect regular expression matches when an alternation of more than 65535 fixed string branches is compiled into a trie in Perl_study_chunk. When such branches are combined into a trie, the delta between the first branch and the shared tail is stored in a 16-bit field. A branch count above 65535 overflows the field, and the trie's match decision table is truncated with no warning or error. A pattern of this shape produces false positive matches (matching strings it should not) and false negative matches (failing to match strings it should). When such a pattern gates an access or filtering decision, the result is wrong.

CVE-2015-8608 (2017-02-07)

The VDir::MapPathA and VDir::MapPathW functions in Perl 5.22 allow remote attackers to cause a denial of service (out-of-bounds read) and possibly execute arbitrary code via a crafted (1) drive letter or (2) pInName argument.

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-2018-6797 (2018-04-17)

An issue was discovered in Perl 5.18 through 5.26. A crafted regular expression can cause a heap-based buffer overflow, with control over the bytes written.

CVE-2018-6913 (2018-04-17)

Heap-based buffer overflow in the pack function in Perl before 5.26.2 allows context-dependent attackers to execute arbitrary code via a large item count.

CVE-2018-18313 (2018-12-07)

Perl before 5.26.3 has a buffer over-read via a crafted regular expression that triggers disclosure of sensitive information from process memory.

CVE-2018-18312 (2018-12-05)

Perl before 5.26.3 and 5.28.0 before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.

CVE-2018-18311 (2018-12-07)

Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.

CVE-2017-12837 (2017-09-19)

Heap-based buffer overflow in the S_regatom function in regcomp.c in Perl 5 before 5.24.3-RC1 and 5.26.x before 5.26.1-RC1 allows remote attackers to cause a denial of service (out-of-bounds write) via a regular expression with a '\\N{}' escape and the case-insensitive modifier.

CVE-2015-8853 (2016-05-25)

The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl before 5.24.0 allow context-dependent attackers to cause a denial of service (infinite loop) via crafted utf-8 data, as demonstrated by "a\x80."

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.

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

our can now have an experimental optional attribute unique

Introduced in Perl 5.8.0

Deprecated in Perl 5.10.0

The ticket for this feature is [perl #119313].

Smart match (~~)

Introduced in Perl 5.10.0

Modified in Perl 5.10.1, 5.12.0

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

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

Lexical $_

Introduced in Perl 5.10.0

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

The ticket for this feature is [perl #119315].

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

Array and hash container functions accept references

Introduced in Perl 5.14.0

The ticket for this feature is [perl #119437].

Lexical subroutines

Introduced in: Perl 5.18

See also: "Lexical Subroutines" in perlsub

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

The ticket for this feature is [perl #120085].

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.

\s in regexp matches vertical tab

Introduced in Perl 5.18

Postfix dereference syntax

Introduced in Perl 5.20.0

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

The ticket for this feature is [perl #120162].

The <:win32> IO pseudolayer

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

See also perlrun

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

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: 5.11.2

Removed in: 5.11.3

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.