SB2026072805 - Improper Handling of Length Parameter Inconsistency in Net::CIDR::Lite

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Handling of Length Parameter Inconsistency (CVE-ID: CVE-2026-40199)

CWE-ID: CWE-130 - Improper Handling of Length Parameter Inconsistency

CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to application 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. 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/b7166b1fa17b3b14b4c795ace5b3fbf71a0bd04a.patch
• https://metacpan.org/release/STIGTSP/Net-CIDR-Lite-0.23/changes
• https://www.cve.org/CVERecord?id=CVE-2026-40198