CVE-2026-40199 Affecting perl-Net-CIDR-Lite package, versions <0.21-150100.6.8.1


Severity

Recommended
0.0
medium
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.31% (24th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-SLES155-PERLNETCIDRLITE-17101852
  • published30 May 2026
  • disclosed29 May 2026

Introduced: 29 May 2026

CVE-2026-40199  (opens in a new tab)

How to fix?

Upgrade SLES:15.5 perl-Net-CIDR-Lite to version 0.21-150100.6.8.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perl-Net-CIDR-Lite package and not the perl-Net-CIDR-Lite package as distributed by SLES. See How to fix? for SLES:15.5 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1