---
id: CVE-2026-106072
title: >-
  A flaw in Node.js TLS hostname verification allows a certificate with only a
  DNS SAN to authenticate an IP endpoint when the client connects using a
  non-canonical IPv4 spelling, such as `0177.0.0.1`, `0x7f.0.0.1`, `2130706433`
  or `127.1`…
summary: >-
  A flaw in Node.js TLS hostname verification allows a certificate with only a
  DNS SAN to authenticate an IP endpoint when the client connects using a
  non-canonical IPv4 spelling, such as `0177.0.0.1`, `0x7f.0.0.1`, `2130706433`
  or `127.1`…
severity: medium
cvss: 6.7
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L'
cvssSource: cna
cwe:
  - CWE-295
vendor: nodejs
product: node
affected:
  - node >= 22.23.3 <= 22.23.3
  - node >= 24.22.0 <= 24.22.0
  - node >= 26.12.0 <= 26.12.0
published: '2026-10-23'
updated: '2026-10-23'
sourceUpdated: '2026-10-23T16:15:05.783Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-106072'
references:
  - url: 'https://nodejs.org/en/blog/vulnerability/october-2026-security-releases'
tags:
  - cve.org
ingestedAt: '2026-10-23T16:31:11.321Z'
---

## Overview

A flaw in Node.js TLS hostname verification allows a certificate with only a DNS SAN to authenticate an IP endpoint when the client connects using a non-canonical IPv4 spelling, such as `0177.0.0.1`, `0x7f.0.0.1`, `2130706433` or `127.1`.

`tls.checkServerIdentity()` did not classify these hosts as IP addresses, but normalized them to their canonical form and matched the result against the certificate DNS names. A certificate containing `DNS:127.0.0.1` and no `IP Address:127.0.0.1` SAN was therefore accepted, while the same certificate is correctly rejected for `127.0.0.1`. Exploitation requires a certificate with a numeric DNS SAN issued by a CA trusted by the client, and a platform resolver that accepts these spellings, such as glibc.

This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.

## Affected

- `node >= 22.23.3 <= 22.23.3`
- `node >= 24.22.0 <= 24.22.0`
- `node >= 26.12.0 <= 26.12.0`

## Remediation

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