Security Advisories (19)
CVE-2016-6185 (2016-08-02)

The XSLoader::load method in XSLoader in Perl does not properly locate .so files when called in a string eval, which might allow local users to execute arbitrary code via a Trojan horse library under the current working directory.

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-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-2018-18314 (2018-12-07)

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

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-2017-12883 (2017-09-19)

Buffer overflow in the S_grok_bslash_N 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 disclose sensitive information or cause a denial of service (application crash) via a crafted regular expression with an invalid '\\N{U+...}' escape.

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.

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.

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.

NAME

lib - manipulate @INC at compile time

SYNOPSIS

use lib LIST;

no lib LIST;

DESCRIPTION

This is a small simple module which simplifies the manipulation of @INC at compile time.

It is typically used to add extra directories to perl's search path so that later use or require statements will find modules which are not located on perl's default search path.

Adding directories to @INC

The parameters to use lib are added to the start of the perl search path. Saying

use lib LIST;

is almost the same as saying

BEGIN { unshift(@INC, LIST) }

For each directory in LIST (called $dir here) the lib module also checks to see if a directory called $dir/$archname/auto exists. If so the $dir/$archname directory is assumed to be a corresponding architecture specific directory and is added to @INC in front of $dir. lib.pm also checks if directories called $dir/$version and $dir/$version/$archname exist and adds these directories to @INC.

The current value of $archname can be found with this command:

perl -V:archname

The corresponding command to get the current value of $version is:

perl -V:version

To avoid memory leaks, all trailing duplicate entries in @INC are removed.

Deleting directories from @INC

You should normally only add directories to @INC. If you need to delete directories from @INC take care to only delete those which you added yourself or which you are certain are not needed by other modules in your script. Other modules may have added directories which they need for correct operation.

The no lib statement deletes all instances of each named directory from @INC.

For each directory in LIST (called $dir here) the lib module also checks to see if a directory called $dir/$archname/auto exists. If so the $dir/$archname directory is assumed to be a corresponding architecture specific directory and is also deleted from @INC.

Restoring original @INC

When the lib module is first loaded it records the current value of @INC in an array @lib::ORIG_INC. To restore @INC to that value you can say

@INC = @lib::ORIG_INC;

CAVEATS

In order to keep lib.pm small and simple, it only works with Unix filepaths. This doesn't mean it only works on Unix, but non-Unix users must first translate their file paths to Unix conventions.

# VMS users wanting to put [.stuff.moo] into 
# their @INC would write
use lib 'stuff/moo';

NOTES

In the future, this module will likely use File::Spec for determining paths, as it does now for Mac OS (where Unix-style or Mac-style paths work, and Unix-style paths are converted properly to Mac-style paths before being added to @INC).

If you try to add a file to @INC as follows:

use lib 'this_is_a_file.txt';

lib will warn about this. The sole exceptions are files with the .par extension which are intended to be used as libraries.

SEE ALSO

FindBin - optional module which deals with paths relative to the source file.

PAR - optional module which can treat .par files as Perl libraries.

AUTHOR

Tim Bunce, 2nd June 1995.

lib is maintained by the perl5-porters. Please direct any questions to the canonical mailing list. Anything that is applicable to the CPAN release can be sent to its maintainer, though.

Maintainer: The Perl5-Porters <perl5-porters@perl.org>

Maintainer of the CPAN release: Steffen Mueller <smueller@cpan.org>

COPYRIGHT AND LICENSE

This package has been part of the perl core since perl 5.001. It has been released separately to CPAN so older installations can benefit from bug fixes.

This package has the same copyright and license as the perl core.