/ 
perl-5.44.0
⭐ Starred 2013 / json_pp
Security Advisories (1)
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.

NAME

json_pp - JSON::PP command utility

SYNOPSIS

json_pp [-v] [-f from_format] [-t to_format] [-json_opt options_to_json1[,options_to_json2[,...]]]

DESCRIPTION

json_pp converts between some input and output formats (one of them is JSON). This program was copied from json_xs and modified.

The default input format is json and the default output format is json with pretty option.

OPTIONS

-f

-f from_format

Reads a data in the given format from STDIN.

Format types:

json

as JSON

eval

as Perl code

-t

Writes a data in the given format to STDOUT.

null

no action.

json

as JSON

dumper

as Data::Dumper

-json_opt

options to JSON::PP

Acceptable options are:

ascii latin1 utf8 pretty indent space_before space_after relaxed canonical allow_nonref
allow_singlequote allow_barekey allow_bignum loose escape_slash indent_length

Multiple options must be separated by commas:

Right: -json_opt pretty,canonical

Wrong: -json_opt pretty -json_opt canonical

-v

Verbose option, but currently no action in fact.

-V

Prints version and exits.

EXAMPLES

$ perl -e'print q|{"foo":"あい","bar":1234567890000000000000000}|' |\
   json_pp -f json -t dumper -json_opt pretty,utf8,allow_bignum

$VAR1 = {
          'bar' => bless( {
                            'value' => [
                                         '0000000',
                                         '0000000',
                                         '5678900',
                                         '1234'
                                       ],
                            'sign' => '+'
                          }, 'Math::BigInt' ),
          'foo' => "\x{3042}\x{3044}"
        };

$ perl -e'print q|{"foo":"あい","bar":1234567890000000000000000}|' |\
   json_pp -f json -t dumper -json_opt pretty

$VAR1 = {
          'bar' => '1234567890000000000000000',
          'foo' => "\x{e3}\x{81}\x{82}\x{e3}\x{81}\x{84}"
        };

SEE ALSO

JSON::PP, json_xs

AUTHOR

Makamaka Hannyaharamitu, <makamaka[at]cpan.org>

COPYRIGHT AND LICENSE

Copyright 2010 by Makamaka Hannyaharamitu

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