/ 
perl-5.27.11
⭐ Starred 2013 / Sub::Util
Security Advisories (13)
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-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-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-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-2026-8376 (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-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-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-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-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.

NAME

Sub::Util - A selection of utility subroutines for subs and CODE references

SYNOPSIS

use Sub::Util qw( prototype set_prototype subname set_subname );

DESCRIPTION

Sub::Util contains a selection of utility subroutines that are useful for operating on subs and CODE references.

The rationale for inclusion in this module is that the function performs some work for which an XS implementation is essential because it cannot be implemented in Pure Perl, and which is sufficiently-widely used across CPAN that its popularity warrants inclusion in a core module, which this is.

FUNCTIONS

prototype

my $proto = prototype( $code )

Since version 1.40.

Returns the prototype of the given $code reference, if it has one, as a string. This is the same as the CORE::prototype operator; it is included here simply for symmetry and completeness with the other functions.

set_prototype

my $code = set_prototype $prototype, $code;

Since version 1.40.

Sets the prototype of the function given by the $code reference, or deletes it if $prototype is undef. Returns the $code reference itself.

Caution: This function takes arguments in a different order to the previous copy of the code from Scalar::Util. This is to match the order of set_subname, and other potential additions in this file. This order has been chosen as it allows a neat and simple chaining of other Sub::Util::set_* functions as might become available, such as:

my $code =
   set_subname   name_here =>
   set_prototype '&@'      =>
   set_attribute ':lvalue' =>
      sub { ...... };

subname

my $name = subname( $code )

Since version 1.40.

Returns the name of the given $code reference, if it has one. Normal named subs will give a fully-qualified name consisting of the package and the localname separated by ::. Anonymous code references will give __ANON__ as the localname. If a name has been set using "set_subname", this name will be returned instead.

This function was inspired by sub_fullname from Sub::Identify. The remaining functions that Sub::Identify implements can easily be emulated using regexp operations, such as

sub get_code_info { return (subname $_[0]) =~ m/^(.+)::(.*?)$/ }
sub sub_name      { return (get_code_info $_[0])[0] }
sub stash_name    { return (get_code_info $_[0])[1] }

Users of Sub::Name beware: This function is not the same as Sub::Name::subname; it returns the existing name of the sub rather than changing it. To set or change a name, see instead "set_subname".

set_subname

my $code = set_subname $name, $code;

Since version 1.40.

Sets the name of the function given by the $code reference. Returns the $code reference itself. If the $name is unqualified, the package of the caller is used to qualify it.

This is useful for applying names to anonymous CODE references so that stack traces and similar situations, to give a useful name rather than having the default of __ANON__. Note that this name is only used for this situation; the set_subname will not install it into the symbol table; you will have to do that yourself if required.

However, since the name is not used by perl except as the return value of caller, for stack traces or similar, there is no actual requirement that the name be syntactically valid as a perl function name. This could be used to attach extra information that could be useful in debugging stack traces.

This function was copied from Sub::Name::subname and renamed to the naming convention of this module.

AUTHOR

The general structure of this module was written by Paul Evans <leonerd@leonerd.org.uk>.

The XS implementation of "set_subname" was copied from Sub::Name by Matthijs van Duin <xmath@cpan.org>