---
id: CVE-2026-101912
title: >-
  ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses
  in JavaScript
summary: >-
  ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses
  in JavaScript. Prior to 10.7.1, the isInSubnet and isHostInSubnet methods in
  src/common.ts compare masked binary strings without validating that both
  operands u…
severity: medium
cvss: 6.3
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'
cwe:
  - CWE-697
  - CWE-843
vendor: beaugunderson
product: ip-address
affected:
  - ip-address < 10.7.1
published: '2026-09-28'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T18:17:21.073'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101912'
references:
  - url: >-
      https://github.com/beaugunderson/ip-address/commit/1343629d57fea413644a5c9d41ff1e59619f3f28
    label: security-advisories@github.com
  - url: 'https://github.com/beaugunderson/ip-address/releases/tag/v10.7.1'
    label: security-advisories@github.com
  - url: >-
      https://github.com/beaugunderson/ip-address/security/advisories/GHSA-j6r3-76f7-8jcv
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
cvssSource: cna
ingestedAt: '2026-09-28T18:17:54.309Z'
---

## Overview

ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses in JavaScript. Prior to 10.7.1, the isInSubnet and isHostInSubnet methods in src/common.ts compare masked binary strings without validating that both operands use the same IP family. A cross-family containment check whose leading address bits match makes the masked strings compare equal even though IPv4 and IPv6 do not share an address space. An allowlist or denylist decision can therefore classify an address outside the intended range as contained. This issue is fixed in version 10.7.1.

## Remediation

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