CPANSA-Net-IP-LPM-2026-56015: Net-IP-LPM vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-07-03T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-07-03T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score 9.1 Severity
Original language Language en
Also referred to

Vulnerability Description

Net::IP::LPM versions through 1.10 for Perl allow a heap out-of-bounds read via an unbounded prefix length. add() passes the prefix string to the trie builder addPrefixToTrie() without checking it against the address width. addPrefixToTrie() then walks the prefix buffer by prefix_length bits, reading prefix[byte] for byte up to prefix_len/8, where prefix is the 4-byte (IPv4) or 16-byte (IPv6) packed address. A prefix length greater than 32 for IPv4 or 128 for IPv6, for example add("1.2.3.4/255", $v) or add("2001:db8::/255", $v), reads past the end of the packed address. The out-of-bounds read happens during trie construction and is bounded: the prefix length is stored as an unsigned char, so the bit walk reads at most 32 bytes from the start of the packed address, a short distance past the end of the 4-byte or 16-byte buffer. It is detectable under AddressSanitizer, valgrind, or a hardened allocator, where it can abort the process. Lookups and dump() format only the valid address width, so the out-of-bounds bytes are not exposed through the module's API.

Vulnerabilities

CVE-2026-56015

Vulnerability Description

Net::IP::LPM versions through 1.10 for Perl allow a heap out-of-bounds read via an unbounded prefix length.

add() passes the prefix string to the trie builder addPrefixToTrie() without checking it against the address width.

addPrefixToTrie() then walks the prefix buffer by prefix_length bits, reading prefix[byte] for byte up to prefix_len/8, where prefix is the 4-byte (IPv4) or 16-byte (IPv6) packed address. A prefix length greater than 32 for IPv4 or 128 for IPv6, for example add("1.2.3.4/255", $v) or add("2001:db8::/255", $v), reads past the end of the packed address.

The out-of-bounds read happens during trie construction and is bounded: the prefix length is stored as an unsigned char, so the bit walk reads at most 32 bytes from the start of the packed address, a short distance past the end of the 4-byte or 16-byte buffer. It is detectable under AddressSanitizer, valgrind, or a hardened allocator, where it can abort the process. Lookups and dump() format only the valid address width, so the out-of-bounds bytes are not exposed through the module's API.

Weakness CWE-125 : Out-of-bounds Read

Product status

Known affected
Product Score
Net-IP-LPM greater than 0
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H 9.1 Critical

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Fri Jul 3 00:00:00 2026 First release

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