/ 
perl-5.41.3
⭐ Starred 2013 / Pod::Escapes
Security Advisories (8)
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-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-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.

NAME

Pod::Escapes - for resolving Pod E<...> sequences

SYNOPSIS

use Pod::Escapes qw(e2char);
...la la la, parsing POD, la la la...
$text = e2char($e_node->label);
unless(defined $text) {
  print "Unknown E sequence \"", $e_node->label, "\"!";
}
...else print/interpolate $text...

DESCRIPTION

This module provides things that are useful in decoding Pod E<...> sequences. Presumably, it should be used only by Pod parsers and/or formatters.

By default, Pod::Escapes exports none of its symbols. But you can request any of them to be exported. Either request them individually, as with use Pod::Escapes qw(symbolname symbolname2...);, or you can do use Pod::Escapes qw(:ALL); to get all exportable symbols.

GOODIES

e2char($e_content)

Given a name or number that could appear in a E<name_or_num> sequence, this returns the string that it stands for. For example, e2char('sol'), e2char('47'), e2char('0x2F'), and e2char('057') all return "/", because E<sol>, E<47>, E<0x2f>, and E<057>, all mean "/". If the name has no known value (as with a name of "qacute") or is syntactically invalid (as with a name of "1/4"), this returns undef.

e2charnum($e_content)

Given a name or number that could appear in a E<name_or_num> sequence, this returns the number of the Unicode character that this stands for. For example, e2char('sol'), e2char('47'), e2char('0x2F'), and e2char('057') all return 47, because E<sol>, E<47>, E<0x2f>, and E<057>, all mean "/", whose Unicode number is 47. If the name has no known value (as with a name of "qacute") or is syntactically invalid (as with a name of "1/4"), this returns undef.

$Name2character{name}

Maps from names (as in E<name>) like "eacute" or "sol" to the string that each stands for. Note that this does not include numerics (like "64" or "x981c"). Under old Perl versions (before 5.7) you get a "?" in place of characters whose Unicode value is over 255.

$Name2character_number{name}

Maps from names (as in E<name>) like "eacute" or "sol" to the Unicode value that each stands for. For example, $Name2character_number{'eacute'} is 201, and $Name2character_number{'eacute'} is 8364. You get the correct Unicode value, regardless of the version of Perl you're using -- which differs from %Name2character's behavior under pre-5.7 Perls.

Note that this hash does not include numerics (like "64" or "x981c").

$Latin1Code_to_fallback{integer}

For numbers in the range 160 (0x00A0) to 255 (0x00FF), this maps from the character code for a Latin-1 character (like 233 for lowercase e-acute) to the US-ASCII character that best aproximates it (like "e"). You may find this useful if you are rendering POD in a format that you think deals well only with US-ASCII characters.

$Latin1Char_to_fallback{character}

Just as above, but maps from characters (like "\xE9", lowercase e-acute) to characters (like "e").

$Code2USASCII{integer}

This maps from US-ASCII codes (like 32) to the corresponding character (like space, for 32). Only characters 32 to 126 are defined. This is meant for use by e2char($x) when it senses that it's running on a non-ASCII platform (where chr(32) doesn't get you a space -- but $Code2USASCII{32} will). It's documented here just in case you might find it useful.

CAVEATS

On Perl versions before 5.7, Unicode characters with a value over 255 (like lambda or emdash) can't be conveyed. This module does work under such early Perl versions, but in the place of each such character, you get a "?". Latin-1 characters (characters 160-255) are unaffected.

Under EBCDIC platforms, e2char($n) may not always be the same as chr(e2charnum($n)), and ditto for $Name2character{$name} and chr($Name2character_number{$name}), because the strings are returned as native, and the numbers are returned as Unicode. However, for Perls starting with v5.8, e2char($n) is the same as chr(utf8::unicode_to_native(e2charnum($n))), and ditto for $Name2character{$name} and chr(utf8::unicode_to_native($Name2character_number{$name})).

SEE ALSO

Pod::Browser - a pod web server based on Catalyst.

Pod::Checker - check pod documents for syntax errors.

Pod::Coverage - check if the documentation for a module is comprehensive.

perlpod - description of pod format (for people documenting with pod).

perlpodspec - specification of pod format (for people processing it).

Text::Unidecode - ASCII transliteration of Unicode text.

REPOSITORY

https://github.com/neilbowers/Pod-Escapes

COPYRIGHT AND DISCLAIMERS

Copyright (c) 2001-2004 Sean M. Burke. All rights reserved.

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

This program is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.

Portions of the data tables in this module are derived from the entity declarations in the W3C XHTML specification.

Currently (October 2001), that's these three:

http://www.w3.org/TR/xhtml1/DTD/xhtml-lat1.ent
http://www.w3.org/TR/xhtml1/DTD/xhtml-special.ent
http://www.w3.org/TR/xhtml1/DTD/xhtml-symbol.ent

AUTHOR

Sean M. Burke sburke@cpan.org

Now being maintained by Neil Bowers <neilb@cpan.org>