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perl-5.42.0
⭐ Starred 2013 / Text::Tabs
Security Advisories (4)
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-2026-13221 (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-2026-4176 (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-2026-8376 (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.

NAME

Text::Tabs - expand and unexpand tabs like unix expand(1) and unexpand(1)

SYNOPSIS

use Text::Tabs;

$tabstop = 4;  # default = 8
@lines_without_tabs = expand(@lines_with_tabs);
@lines_with_tabs = unexpand(@lines_without_tabs);

DESCRIPTION

Text::Tabs does most of what the unix utilities expand(1) and unexpand(1) do. Given a line with tabs in it, expand replaces those tabs with the appropriate number of spaces. Given a line with or without tabs in it, unexpand adds tabs when it can save bytes by doing so, like the unexpand -a command.

Unlike the old unix utilities, this module correctly accounts for any Unicode combining characters (such as diacriticals) that may occur in each line for both expansion and unexpansion. These are overstrike characters that do not increment the logical position. Make sure you have the appropriate Unicode settings enabled.

EXPORTS

The following are exported:

expand
unexpand
$tabstop

The $tabstop variable controls how many column positions apart each tabstop is. The default is 8.

Please note that local($tabstop) doesn't do the right thing and if you want to use local to override $tabstop, you need to use local($Text::Tabs::tabstop).

EXAMPLE

#!perl
# unexpand -a
use Text::Tabs;

while (<>) {
  print unexpand $_;
}

Instead of the shell's expand command, use:

perl -MText::Tabs -n -e 'print expand $_'

Instead of the shell's unexpand -a command, use:

perl -MText::Tabs -n -e 'print unexpand $_'

BUGS

Text::Tabs handles only tabs ("\t") and combining characters (/\pM/). It doesn't count backwards for backspaces ("\t"), omit other non-printing control characters (/\pC/), or otherwise deal with any other zero-, half-, and full-width characters.

LICENSE

Copyright (C) 1996-2002,2005,2006 David Muir Sharnoff. Copyright (C) 2005 Aristotle Pagaltzis Copyright (C) 2012-2013 Google, Inc. This module may be modified, used, copied, and redistributed at your own risk. Although allowed by the preceding license, please do not publicly redistribute modified versions of this code with the name "Text::Tabs" unless it passes the unmodified Text::Tabs test suite.