CVE-2026-106069

nodejs: nodejs: TLS certificate hostname bypass via non-canonical IP hostnames

Published Oct 23, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
Description
A flaw in Node.js TLS hostname verification can cause a server certificate to be validated against a different IP address than the one the client connected to, when the host is a non-canonical IPv4 literal with a leading zero, such as `0127.0.0.1`.

`tls.checkServerIdentity()` normalizes the host following the WHATWG URL rules, which read a leading-zero octet as octal (`0127.0.0.1` becomes `87.0.0.1`), while the connection is made through the operating system resolver, which on some platforms such as macOS reads it as decimal (`127.0.0.1`). A server at the connected address can then be authenticated with a certificate issued for another IP address.

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

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Node.js TLS Hostname Verification Mismatch for Leading-Zero IPv4 Addresses nodejs: nodejs: TLS certificate hostname bypass via non-canonical IP hostnames
Weaknesses CWE-297
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

threat_severity

Important

Type Values Removed Values Added
First Time appeared Nodejs
Nodejs nodejs
Vendors & Products Nodejs
Nodejs nodejs
Type Values Removed Values Added
Title Node.js TLS Hostname Verification Mismatch for Leading-Zero IPv4 Addresses
Type Values Removed Values Added
Description A flaw in Node.js TLS hostname verification can cause a server certificate to be validated against a different IP address than the one the client connected to, when the host is a non-canonical IPv4 literal with a leading zero, such as `0127.0.0.1`. `tls.checkServerIdentity()` normalizes the host following the WHATWG URL rules, which read a leading-zero octet as octal (`0127.0.0.1` becomes `87.0.0.1`), while the connection is made through the operating system resolver, which on some platforms such as macOS reads it as decimal (`127.0.0.1`). A server at the connected address can then be authenticated with a certificate issued for another IP address. This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.
Weaknesses CWE-295
References
Metrics cvssV3_0

{'score': 7.4, 'vector': 'CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
hackerone
Published
Updated
Nov 2, 2026, 1:31 PM
Reserved
Oct 6, 2026, 3:00 PM
Status
Awaiting Analysis
Published
Oct 23, 2026, 5:17 PM
Modified
Nov 2, 2026, 2:17 PM
Severity
Important
Public date
Oct 21, 2026, 12:00 AM