---
id: CVE-2026-86287
title: |-
  Net::IP::LPM versions before 1.12 for Perl accept malformed prefix lengths.

  Non-numeric and non-ASCII prefix lengths are accepted and treated as 0
summary: >-
  Net::IP::LPM versions before 1.12 for Perl accept malformed prefix lengths.


  Non-numeric and non-ASCII prefix lengths are accepted and treated as 0.
  Integers over 31 bits are silently truncated.  A single malformed mask will
  poison the l…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-1287
product: Net-IP-LPM
affected:
  - Net-IP-LPM < 1.12
published: '2026-09-07'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T19:20:13.267'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86287'
references:
  - url: >-
      https://github.com/robrwo/perl-Net-IP-LPM/commit/814f8baa85537827db8c3b3d251e48db7aca318f.patch
    label: 9b29abf9-4ab0-4765-b253-1875cd9b441e
  - url: 'https://metacpan.org/release/RRWO/Net-IP-LPM-1.12/changes'
    label: 9b29abf9-4ab0-4765-b253-1875cd9b441e
  - url: 'http://www.openwall.com/lists/oss-security/2026/09/07/1'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-08T18:40:16.712696Z'
epss: 0.00385
epssPercentile: 0.3245
ingestedAt: '2026-09-08T15:33:26.980Z'
---

## Overview

Net::IP::LPM versions before 1.12 for Perl accept malformed prefix lengths.

Non-numeric and non-ASCII prefix lengths are accepted and treated as 0. Integers over 31 bits are silently truncated.  A single malformed mask will poison the lookup table.

The result is that the lookup will silently succeed for every address. An allow-list will allow every address, and a deny-list will block every address.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.