/ 
Net-CIDR-Lite-0.22
/ Net::CIDR::Lite
Security Advisories (4)
CVE-2026-40198 (2026-04-10)

Net::CIDR::Lite versions before 0.23 for Perl does not validate IPv6 group count, which may allow IP ACL bypass. _pack_ipv6() does not check that uncompressed IPv6 addresses (without ::) have exactly 8 hex groups. Inputs like "abcd", "1:2:3", or "1:2:3:4:5:6:7" are accepted and produce packed values of wrong length (3, 7, or 15 bytes instead of 17). The packed values are used internally for mask and comparison operations. find() and bin_find() use Perl string comparison (lt/gt) on these values, and comparing strings of different lengths gives wrong results. This can cause find() to incorrectly report an address as inside or outside a range. Example: my $cidr = Net::CIDR::Lite->new("::/8"); $cidr->find("1:2:3"); # invalid input, incorrectly returns true This is the same class of input validation issue as CVE-2021-47154 (IPv4 leading zeros) previously fixed in this module. See also CVE-2026-40199, a related issue in the same function affecting IPv4 mapped IPv6 addresses.

CVE-2026-40199 (2026-04-10)

Net::CIDR::Lite versions before 0.23 for Perl mishandles IPv4 mapped IPv6 addresses, which may allow IP ACL bypass. _pack_ipv6() includes the sentinel byte from _pack_ipv4() when building the packed representation of IPv4 mapped addresses like ::ffff:192.168.1.1. This produces an 18 byte value instead of 17 bytes, misaligning the IPv4 part of the address. The wrong length causes incorrect results in mask operations (bitwise AND truncates to the shorter operand) and in find() / bin_find() which use Perl string comparison (lt/gt). This can cause find() to incorrectly match or miss addresses. Example: my $cidr = Net::CIDR::Lite->new("::ffff:192.168.1.0/120"); $cidr->find("::ffff:192.168.2.0"); # incorrectly returns true This is triggered by valid RFC 4291 IPv4 mapped addresses (::ffff:x.x.x.x). See also CVE-2026-40198, a related issue in the same function affecting malformed IPv6 addresses.

CVE-2026-45190 (2026-05-10)

Net::CIDR::Lite versions before 0.24 for Perl does not properly validate IP address and CIDR mask inputs, which may allow IP ACL bypass. Inputs containing a trailing newline or non-ASCII digit characters pass the validators but are then re-encoded by the parser to a different address than the input string spelled. find() and bin_find() can match or miss addresses as a result. Example: my $cidr = Net::CIDR::Lite->new(); $cidr->add("::1\n/128"); $cidr->find("::1a"); # incorrectly returns true See also CVE-2026-45191.

CVE-2026-45191 (2026-05-10)

Net::CIDR::Lite versions before 0.24 for Perl does not properly consider extraneous zero characters in CIDR mask values, which may allow IP ACL bypass. Mask forms like "/00" and "/01" pass validation and parse to the same prefix as their unpadded value. See also CVE-2026-45190.

NAME

Net::CIDR::Lite - Perl extension for merging IPv4 or IPv6 CIDR addresses

SYNOPSIS

use Net::CIDR::Lite;

my $cidr = Net::CIDR::Lite->new;
$cidr->add($cidr_address);
@cidr_list = $cidr->list;
@ip_ranges = $cidr->list_range;

DESCRIPTION

Faster alternative to Net::CIDR when merging a large number of CIDR address ranges. Works for IPv4 and IPv6 addresses.

METHODS

new()
$cidr = Net::CIDR::Lite->new
$cidr = Net::CIDR::Lite->new(@args)

Creates an object to represent a list of CIDR address ranges. No particular format is set yet; once an add method is called with a IPv4 or IPv6 format, only that format may be added for this cidr object. Any arguments supplied are passed to add_any() (see below).

add()
$cidr->add($cidr_address)

Adds a CIDR address range to the list.

add_range()
$cidr->add_range($ip_range)

Adds a hyphenated IP address range to the list.

add_cidr()
$cidr1->add_cidr($cidr2)

Adds address ranges from one object to another object.

add_ip()
$cidr->add_ip($ip_address)

Adds a single IP address to the list.

add_any()
$cidr->add_any($cidr_or_range_or_address);

Determines format of range or single ip address and calls add(), add_range(), add_cidr(), or add_ip() as appropriate.

$cidr->clean()
$cidr->clean;

If you are going to call the list method more than once on the same data, then for optimal performance, you can call this to purge null nodes in overlapping ranges from the list. Boundary nodes in contiguous ranges are automatically purged during add(). Only useful when ranges overlap or when contiguous ranges are added out of order.

$cidr->list()
@cidr_list = $cidr->list;
$list_ref  = $cidr->list;

Returns a list of the merged CIDR addresses. Returns an array if called in list context, an array reference if not.

$cidr->list_range()
@cidr_list = $cidr->list_range;
$list_ref  = $cidr->list_range;

Returns a list of the merged addresses, but in hyphenated range format. Returns an array if called in list context, an array reference if not.

$cidr->list_short_range()
@cidr_list = $cidr->list_short_range;
$list_ref  = $cidr->list_short_range;

Returns a list of the C subnet merged addresses, in short hyphenated range format. Returns an array if called in list context, an array reference if not.

Example:

1.1.1.1-2
1.1.1.5-7
1.1.1.254-255
1.1.2.0-2
1.1.3.5
1.1.3.7
$cidr->find()
$found = $cidr->find($ip);

Returns true if the ip address is found in the CIDR range. False if not. Not extremely efficient, is O(n*log(n)) to sort the ranges in the cidr object O(n) to search through the ranges in the cidr object. The sort is cached on the first call and used in subsequent calls, but if more addresses are added to the cidr object, prep_find() must be called on the cidr object.

$cidr->bin_find()

Same as find(), but forces a binary search. See also prep_find.

$cidr->prep_find()
$cidr->prep_find($num);

Caches the result of sorting the ip addresses. Implicitly called on the first find call, but must be explicitly called if more addresses are added to the cidr object. find() will do a binary search if the number of ranges is greater than or equal to $num (default 20);

$cidr->spanner()
$spanner = $cidr1->spanner($label1, $cidr2, $label2, ...);

Creates a spanner object to find out if multiple ip addresses are within multiple labeled address ranges. May also be called as (with or without any arguments):

Net::CIDR::Lite::Span->new($cidr1, $label1, $cidr2, $label2, ...);
$spanner->add()
$spanner->add($cidr1, $label1, $cidr2, $label2,...);

Adds labeled address ranges to the spanner object. The 'address range' may be a Net::CIDR::Lite object, a single CIDR address range, a single hyphenated IP address range, or a single IP address.

$spanner->find()
$href = $spanner->find(@ip_addresses);

Look up which range(s) ip addresses are in, and return a lookup table of the results, with the keys being the ip addresses, and the value a hash reference of which address ranges the ip address is in.

$spanner->bin_find()

Same as find(), but forces a binary search. See also prep_find.

$spanner->prep_find()
$spanner->prep_find($num);

Called implicitly the first time $spanner->find(..) is called, must be called again if more cidr objects are added to the spanner object. Will do a binary search if ratio of the number of ip addresses to the number of ranges is less than $num percent (default 4).

$spanner->clean()
$clean_address = $spanner->clean($ip_address);

Validates and returns a cleaned up version of an ip address (which is what you will find as the key in the result from the $spanner->find(..), not necessarily what the original argument looked like). E.g. removes unnecessary leading zeros, removes null blocks from IPv6 addresses, etc.

CAVEATS

Garbage in/garbage out. This module does do validation, but maybe not enough to suit your needs.

AUTHOR

Douglas Wilson, <dougw@cpan.org> w/numerous hints and ideas borrowed from Tye McQueen.

MAINTAINER

Stig Palmquist <stig@stig.io>

COPYRIGHT

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

SEE ALSO

Net::CIDR.