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CVE-2026-40198 Detail

Description

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.


Metrics

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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

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URL Source(s) Tag(s)
https://github.com/stigtsp/Net-CIDR-Lite/commit/25d65f85dbe4885959a10471725ec9d250a589c3.patch CPANSec
https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes CPANSec
https://www.cve.org/CVERecord?id=CVE-2026-40199 CPANSec

Weakness Enumeration

CWE-ID CWE Name Source
CWE-1286 Improper Validation of Syntactic Correctness of Input CPANSec  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-40198
NVD Published Date:
04/10/2026
NVD Last Modified:
04/10/2026
Source:
CPANSec