/ 
perl-5.36.0
⭐ Starred 2013 / Pod::Text
Security Advisories (11)
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-2023-47038 (2023-10-30)

A crafted regular expression when compiled by perl 5.30.0 through 5.38.0 can cause a one attacker controlled byte buffer overflow in a heap allocated buffer

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-2026-8376 (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-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.

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-2026-57432 (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

Pod::Text - Convert POD data to formatted text

SYNOPSIS

use Pod::Text;
my $parser = Pod::Text->new (sentence => 1, width => 78);

# Read POD from STDIN and write to STDOUT.
$parser->parse_from_filehandle;

# Read POD from file.pod and write to file.txt.
$parser->parse_from_file ('file.pod', 'file.txt');

DESCRIPTION

Pod::Text is a module that can convert documentation in the POD format (the preferred language for documenting Perl) into formatted text. It uses no special formatting controls or codes whatsoever, and its output is therefore suitable for nearly any device.

As a derived class from Pod::Simple, Pod::Text supports the same methods and interfaces. See Pod::Simple for all the details; briefly, one creates a new parser with Pod::Text->new() and then normally calls parse_file().

new() can take options, in the form of key/value pairs, that control the behavior of the parser. The currently recognized options are:

alt

If set to a true value, selects an alternate output format that, among other things, uses a different heading style and marks =item entries with a colon in the left margin. Defaults to false.

code

If set to a true value, the non-POD parts of the input file will be included in the output. Useful for viewing code documented with POD blocks with the POD rendered and the code left intact.

errors

How to report errors. die says to throw an exception on any POD formatting error. stderr says to report errors on standard error, but not to throw an exception. pod says to include a POD ERRORS section in the resulting documentation summarizing the errors. none ignores POD errors entirely, as much as possible.

The default is pod.

indent

The number of spaces to indent regular text, and the default indentation for =over blocks. Defaults to 4.

loose

If set to a true value, a blank line is printed after a =head1 heading. If set to false (the default), no blank line is printed after =head1, although one is still printed after =head2. This is the default because it's the expected formatting for manual pages; if you're formatting arbitrary text documents, setting this to true may result in more pleasing output.

margin

The width of the left margin in spaces. Defaults to 0. This is the margin for all text, including headings, not the amount by which regular text is indented; for the latter, see the indent option. To set the right margin, see the width option.

nourls

Normally, L<> formatting codes with a URL but anchor text are formatted to show both the anchor text and the URL. In other words:

L<foo|http://example.com/>

is formatted as:

foo <http://example.com/>

This option, if set to a true value, suppresses the URL when anchor text is given, so this example would be formatted as just foo. This can produce less cluttered output in cases where the URLs are not particularly important.

quotes

Sets the quote marks used to surround C<> text. If the value is a single character, it is used as both the left and right quote. Otherwise, it is split in half, and the first half of the string is used as the left quote and the second is used as the right quote.

This may also be set to the special value none, in which case no quote marks are added around C<> text.

sentence

If set to a true value, Pod::Text will assume that each sentence ends in two spaces, and will try to preserve that spacing. If set to false, all consecutive whitespace in non-verbatim paragraphs is compressed into a single space. Defaults to false.

stderr

Send error messages about invalid POD to standard error instead of appending a POD ERRORS section to the generated output. This is equivalent to setting errors to stderr if errors is not already set. It is supported for backward compatibility.

utf8

By default, Pod::Text uses the same output encoding as the input encoding of the POD source (provided that Perl was built with PerlIO; otherwise, it doesn't encode its output). If this option is given, the output encoding is forced to UTF-8.

Be aware that, when using this option, the input encoding of your POD source should be properly declared unless it's US-ASCII. Pod::Simple will attempt to guess the encoding and may be successful if it's Latin-1 or UTF-8, but it will produce warnings. Use the =encoding command to declare the encoding. See perlpod(1) for more information.

width

The column at which to wrap text on the right-hand side. Defaults to 76.

The standard Pod::Simple method parse_file() takes one argument naming the POD file to read from. By default, the output is sent to STDOUT, but this can be changed with the output_fh() method.

The standard Pod::Simple method parse_from_file() takes up to two arguments, the first being the input file to read POD from and the second being the file to write the formatted output to.

You can also call parse_lines() to parse an array of lines or parse_string_document() to parse a document already in memory. As with parse_file(), parse_lines() and parse_string_document() default to sending their output to STDOUT unless changed with the output_fh() method. Be aware that parse_lines() and parse_string_document() both expect raw bytes, not decoded characters.

To put the output from any parse method into a string instead of a file handle, call the output_string() method instead of output_fh().

See Pod::Simple for more specific details on the methods available to all derived parsers.

DIAGNOSTICS

Bizarre space in item
Item called without tag

(W) Something has gone wrong in internal =item processing. These messages indicate a bug in Pod::Text; you should never see them.

Can't open %s for reading: %s

(F) Pod::Text was invoked via the compatibility mode pod2text() interface and the input file it was given could not be opened.

Invalid errors setting "%s"

(F) The errors parameter to the constructor was set to an unknown value.

Invalid quote specification "%s"

(F) The quote specification given (the quotes option to the constructor) was invalid. A quote specification must be either one character long or an even number (greater than one) characters long.

POD document had syntax errors

(F) The POD document being formatted had syntax errors and the errors option was set to die.

BUGS

Encoding handling assumes that PerlIO is available and does not work properly if it isn't. The utf8 option is therefore not supported unless Perl is built with PerlIO support.

CAVEATS

If Pod::Text is given the utf8 option, the encoding of its output file handle will be forced to UTF-8 if possible, overriding any existing encoding. This will be done even if the file handle is not created by Pod::Text and was passed in from outside. This maintains consistency regardless of PERL_UNICODE and other settings.

If the utf8 option is not given, the encoding of its output file handle will be forced to the detected encoding of the input POD, which preserves whatever the input text is. This ensures backward compatibility with earlier, pre-Unicode versions of this module, without large numbers of Perl warnings.

This is not ideal, but it seems to be the best compromise. If it doesn't work for you, please let me know the details of how it broke.

NOTES

This is a replacement for an earlier Pod::Text module written by Tom Christiansen. It has a revamped interface, since it now uses Pod::Simple, but an interface roughly compatible with the old Pod::Text::pod2text() function is still available. Please change to the new calling convention, though.

The original Pod::Text contained code to do formatting via termcap sequences, although it wasn't turned on by default and it was problematic to get it to work at all. This rewrite doesn't even try to do that, but a subclass of it does. Look for Pod::Text::Termcap.

AUTHOR

Russ Allbery <rra@cpan.org>, based very heavily on the original Pod::Text by Tom Christiansen <tchrist@mox.perl.com> and its conversion to Pod::Parser by Brad Appleton <bradapp@enteract.com>. Sean Burke's initial conversion of Pod::Man to use Pod::Simple provided much-needed guidance on how to use Pod::Simple.

COPYRIGHT AND LICENSE

Copyright 1999-2002, 2004, 2006, 2008-2009, 2012-2016, 2018-2019 Russ Allbery <rra@cpan.org>

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

SEE ALSO

Pod::Simple, Pod::Text::Termcap, perlpod(1), pod2text(1)

The current version of this module is always available from its web site at https://www.eyrie.org/~eagle/software/podlators/. It is also part of the Perl core distribution as of 5.6.0.