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perl-5.27.11
⭐ Starred 2013 / ExtUtils::ParseXS::Utilities
Security Advisories (13)
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-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-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-2026-15534 (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-2026-19487 (2026-08-13)

Perl versions from 5.9.4 before 5.41.9 produce incorrect regular expression match results when a stale failure flag ends the Aho-Corasick prescan early in S_find_byclass. The prescan walks the subject for positions where the full pattern could match, and the engine tries it from the leftmost one recorded. A failing transition sets the failed flag, and a later successful transition does not clear it, so the prescan reads the stale flag as a failure and stops before it can record a candidate that starts earlier. It takes a subject where one candidate is recorded and a later character then forces a fallback through a fail link that succeeds. Example: "ABCDE" =~ m/ABCF|BCDE|C/; # matches C at offset 2, not BCDE "ABCDE" =~ m/ABCF|BCDE|C(G)/; # no match, BCDE missed An alternation like this can miss input it should match, or match it on the wrong branch, so an access or filtering decision made from the result can be wrong.

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.

NAME

ExtUtils::ParseXS::Utilities - Subroutines used with ExtUtils::ParseXS

SYNOPSIS

use ExtUtils::ParseXS::Utilities qw(
  standard_typemap_locations
  trim_whitespace
  C_string
  valid_proto_string
  process_typemaps
  map_type
  standard_XS_defs
  assign_func_args
  analyze_preprocessor_statements
  set_cond
  Warn
  blurt
  death
  check_conditional_preprocessor_statements
  escape_file_for_line_directive
  report_typemap_failure
);

SUBROUTINES

The following functions are not considered to be part of the public interface. They are documented here for the benefit of future maintainers of this module.

standard_typemap_locations()

  • Purpose

    Provide a list of filepaths where typemap files may be found. The filepaths -- relative paths to files (not just directory paths) -- appear in this list in lowest-to-highest priority.

    The highest priority is to look in the current directory.

    'typemap'

    The second and third highest priorities are to look in the parent of the current directory and a directory called lib/ExtUtils underneath the parent directory.

    '../typemap',
'../lib/ExtUtils/typemap',

    The fourth through ninth highest priorities are to look in the corresponding grandparent, great-grandparent and great-great-grandparent directories.

    '../../typemap',
'../../lib/ExtUtils/typemap',
'../../../typemap',
'../../../lib/ExtUtils/typemap',
'../../../../typemap',
'../../../../lib/ExtUtils/typemap',

    The tenth and subsequent priorities are to look in directories named ExtUtils which are subdirectories of directories found in @INC -- provided a file named typemap actually exists in such a directory. Example:

    '/usr/local/lib/perl5/5.10.1/ExtUtils/typemap',

    However, these filepaths appear in the list returned by standard_typemap_locations() in reverse order, i.e., lowest-to-highest.

    '/usr/local/lib/perl5/5.10.1/ExtUtils/typemap',
'../../../../lib/ExtUtils/typemap',
'../../../../typemap',
'../../../lib/ExtUtils/typemap',
'../../../typemap',
'../../lib/ExtUtils/typemap',
'../../typemap',
'../lib/ExtUtils/typemap',
'../typemap',
'typemap'

  • Arguments

    my @stl = standard_typemap_locations( \@INC );

    Reference to @INC.

  • Return Value

    Array holding list of directories to be searched for typemap files.

trim_whitespace()

  • Purpose

    Perform an in-place trimming of leading and trailing whitespace from the first argument provided to the function.

  • Argument

    trim_whitespace($arg);

  • Return Value

    None. Remember: this is an in-place modification of the argument.

C_string()

  • Purpose

    Escape backslashes (\) in prototype strings.

  • Arguments

    $ProtoThisXSUB = C_string($_);

    String needing escaping.

  • Return Value

    Properly escaped string.

valid_proto_string()

  • Purpose

    Validate prototype string.

  • Arguments

    String needing checking.

  • Return Value

    Upon success, returns the same string passed as argument.

    Upon failure, returns 0.

process_typemaps()

  • Purpose

    Process all typemap files.

  • Arguments

    my $typemaps_object = process_typemaps( $args{typemap}, $pwd );

    List of two elements: typemap element from %args; current working directory.

  • Return Value

    Upon success, returns an ExtUtils::Typemaps object.

map_type()

  • Purpose

    Performs a mapping at several places inside PARAGRAPH loop.

  • Arguments

    $type = map_type($self, $type, $varname);

    List of three arguments.

  • Return Value

    String holding augmented version of second argument.

standard_XS_defs()

  • Purpose

    Writes to the .c output file certain preprocessor directives and function headers needed in all such files.

  • Arguments

    None.

  • Return Value

    Returns true.

assign_func_args()

  • Purpose

    Perform assignment to the func_args attribute.

  • Arguments

    $string = assign_func_args($self, $argsref, $class);

    List of three elements. Second is an array reference; third is a string.

  • Return Value

    String.

analyze_preprocessor_statements()

  • Purpose

    Within each function inside each Xsub, print to the .c output file certain preprocessor statements.

  • Arguments

    ( $self, $XSS_work_idx, $BootCode_ref ) =
  analyze_preprocessor_statements(
    $self, $statement, $XSS_work_idx, $BootCode_ref
  );

    List of four elements.

  • Return Value

    Modifed values of three of the arguments passed to the function. In particular, the XSStack and InitFileCode attributes are modified.

set_cond()

  • Purpose

  • Arguments

  • Return Value

current_line_number()

  • Purpose

    Figures out the current line number in the XS file.

  • Arguments

    $self

  • Return Value

    The current line number.

Warn()

  • Purpose

  • Arguments

  • Return Value

blurt()

  • Purpose

  • Arguments

  • Return Value

death()

  • Purpose

  • Arguments

  • Return Value

check_conditional_preprocessor_statements()

  • Purpose

  • Arguments

  • Return Value

escape_file_for_line_directive()

  • Purpose

    Escapes a given code source name (typically a file name but can also be a command that was read from) so that double-quotes and backslashes are escaped.

  • Arguments

    A string.

  • Return Value

    A string with escapes for double-quotes and backslashes.

report_typemap_failure

  • Purpose

    Do error reporting for missing typemaps.

  • Arguments

    The ExtUtils::ParseXS object.

    An ExtUtils::Typemaps object.

    The string that represents the C type that was not found in the typemap.

    Optionally, the string death or blurt to choose whether the error is immediately fatal or not. Default: blurt

  • Return Value

    Returns nothing. Depending on the arguments, this may call death or blurt, the former of which is fatal.