CVE-2026-40198 Affecting perl-Net-CIDR-Lite package, versions <0:0.22-8.amzn2023.0.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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-AMZN2023-PERLNETCIDRLITE-16352401
- published3 May 2026
- disclosed10 Apr 2026
Introduced: 10 Apr 2026
CVE-2026-40198 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2023 perl-Net-CIDR-Lite to version 0:0.22-8.amzn2023.0.1 or higher.
This issue was patched in ALAS2023-2026-1624.
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 Amazon-Linux.
See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.
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.