CVE-2026-42338

ip-address is a library for parsing and manipulating IPv4 and IPv6 addresses in JavaScript. Prior to 10.1.1, Address6.group() and Address6.link() do not HTML-escape attacker-controlled content before embedding it in the HTML strings they return, and AddressError.parseMessage (emitted by the Address6 constructor for invalid input) can contain unescaped attacker-controlled content in one branch. An application that (1) passes untrusted input to Address6 and (2) renders the output of these methods, or the thrown error's parseMessage, as HTML (e.g. via innerHTML) is vulnerable to cross-site scripting. This vulnerability is fixed in 10.1.1.

What this means for your business

It affects Beaugunderson Ip-Address. It matters if your company, or a supplier that handles your data, runs it.
Code showing how to exploit it has been published, but real attacks have not been confirmed.
An attacker can use it remotely, over a network, without a login, but only after tricking someone into an action such as opening a file or a link.
FIRST's prediction model gives it a 0.5% chance of attack attempts being seen in the next 30 days, ranking above 39% of all known flaws.

What to do

1Check whether your company or your suppliers run Beaugunderson Ip-Address, and which version. The affected versions are listed further down this page.
2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

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Scoring

CVSS: 6.1 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CVSS v4: 5.3
Weakness: CWE-79
Assigned by: security-advisories@github.com

Dates

Published: 2026-05-12
Last modified: 2026-09-11
Sources: NVD

Affected products

Beaugunderson Ip-Address- 10.1.1

As listed in the NVD configuration data. Not a statement about your estate.