/ 
perl-5.40.1
⭐ Starred 2013 / ExtUtils::ParseXS
Security Advisories (6)
CVE-2024-56406 (2025-04-13)

A heap buffer overflow vulnerability was discovered in Perl. Release branches 5.34, 5.36, 5.38 and 5.40 are affected, including development versions from 5.33.1 through 5.41.10. 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-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-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-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.

NAME

ExtUtils::ParseXS - converts Perl XS code into C code

SYNOPSIS

use ExtUtils::ParseXS;

my $pxs = ExtUtils::ParseXS->new;
$pxs->process_file( filename => 'foo.xs' );

$pxs->process_file( filename => 'foo.xs',
                    output => 'bar.c',
                    'C++' => 1,
                    typemap => 'path/to/typemap',
                    hiertype => 1,
                    except => 1,
                    versioncheck => 1,
                    linenumbers => 1,
                    optimize => 1,
                    prototypes => 1,
                    die_on_error => 0,
                  );

# Legacy non-OO interface using a singleton:
use ExtUtils::ParseXS qw(process_file);
process_file( filename => 'foo.xs' );

DESCRIPTION

ExtUtils::ParseXS will compile XS code into C code by embedding the constructs necessary to let C functions manipulate Perl values and creates the glue necessary to let Perl access those functions. The compiler uses typemaps to determine how to map C function parameters and variables to Perl values.

The compiler will search for typemap files called typemap. It will use the following search path to find default typemaps, with the rightmost typemap taking precedence.

../../../typemap:../../typemap:../typemap:typemap

EXPORT

None by default. process_file() and/or report_error_count() may be exported upon request. Using the functional interface is discouraged.

METHODS

$pxs->new()

Returns a new, empty XS parser/compiler object.

$pxs->process_file()

This method processes an XS file and sends output to a C file. The method may be called as a function (this is the legacy interface) and will then use a singleton as invocant.

Named parameters control how the processing is done. The following parameters are accepted:

C++

Adds extern "C" to the C code. Default is false.

hiertype

Retains :: in type names so that C++ hierarchical types can be mapped. Default is false.

except

Adds exception handling stubs to the C code. Default is false.

typemap

Indicates that a user-supplied typemap should take precedence over the default typemaps. A single typemap may be specified as a string, or multiple typemaps can be specified in an array reference, with the last typemap having the highest precedence.

prototypes

Generates prototype code for all xsubs. Default is false.

versioncheck

Makes sure at run time that the object file (derived from the .xs file) and the .pm files have the same version number. Default is true.

linenumbers

Adds #line directives to the C output so error messages will look like they came from the original XS file. Default is true.

optimize

Enables certain optimizations. The only optimization that is currently affected is the use of targets by the output C code (see perlguts). Not optimizing may significantly slow down the generated code, but this is the way xsubpp of 5.005 and earlier operated. Default is to optimize.

inout

Enable recognition of IN, OUT_LIST and INOUT_LIST declarations. Default is true.

argtypes

Enable recognition of ANSI-like descriptions of function signature. Default is true.

s

Maintainer note: I have no clue what this does. Strips function prefixes?

die_on_error

Normally ExtUtils::ParseXS will terminate the program with an exit(1) after printing the details of the exception to STDERR via (warn). This can be awkward when it is used programmatically and not via xsubpp, so this option can be used to cause it to die instead by providing a true value. When not provided this defaults to the value of $ExtUtils::ParseXS::DIE_ON_ERROR which in turn defaults to false.

$pxs->report_error_count()

This method returns the number of [a certain kind of] errors encountered during processing of the XS file.

The method may be called as a function (this is the legacy interface) and will then use a singleton as invocant.

AUTHOR

Based on xsubpp code, written by Larry Wall.

Maintained by:

  • Ken Williams, <ken@mathforum.org>

  • David Golden, <dagolden@cpan.org>

  • James Keenan, <jkeenan@cpan.org>

  • Steffen Mueller, <smueller@cpan.org>

COPYRIGHT

Copyright 2002-2014 by Ken Williams, David Golden and other contributors. All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Based on the ExtUtils::xsubpp code by Larry Wall and the Perl 5 Porters, which was released under the same license terms.

SEE ALSO

perl, ExtUtils::xsubpp, ExtUtils::MakeMaker, perlxs, perlxstut.