SB2026072806 - Improper Validation of Syntactic Correctness of Input in Net::CIDR::Lite

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Validation of Syntactic Correctness of Input (CVE-ID: CVE-2026-40198)

CWE-ID: CWE-1286 - Improper Validation of Syntactic Correctness of Input

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to gain access to modify data on the system.

The vulnerability exists due to the application 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. A remote attacker can gain unauthorized access to sensitive information on the system.

Remediation

Install update from vendor's website.

References

• https://github.com/stigtsp/Net-CIDR-Lite/commit/25d65f85dbe4885959a10471725ec9d250a589c3.patch
• https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes
• https://www.cve.org/CVERecord?id=CVE-2026-40199