A flaw in Node.js TLS hostname verification allows a certificate without a matching IP address SAN to authenticate a connection to an IPv4 address when the host is written with non-ASCII characters, such as fullwidth digits (`127.0.0.1`).

`tls.checkServerIdentity()` did not recognize such hosts as IP addresses, even though they normalize and resolve to a regular IPv4 address, and matched them against the certificate DNS names and Common Name instead. A certificate containing `DNS:127.0.0.1` or `DNS:*.0.0.1` could therefore be accepted for an IP endpoint it was not issued for. This is a regression introduced after the fix for CVE-2026-48618.

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

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Fixes

Solution

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Workaround

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History

Fri, 23 Oct 2026 17:45:00 +0000

Type Values Removed Values Added
Title Node.js TLS Hostname Verification Bypass with Non‑ASCII IP Hostnames

Fri, 23 Oct 2026 16:30:00 +0000

Type Values Removed Values Added
Description A flaw in Node.js TLS hostname verification allows a certificate without a matching IP address SAN to authenticate a connection to an IPv4 address when the host is written with non-ASCII characters, such as fullwidth digits (`127.0.0.1`). `tls.checkServerIdentity()` did not recognize such hosts as IP addresses, even though they normalize and resolve to a regular IPv4 address, and matched them against the certificate DNS names and Common Name instead. A certificate containing `DNS:127.0.0.1` or `DNS:*.0.0.1` could therefore be accepted for an IP endpoint it was not issued for. This is a regression introduced after the fix for CVE-2026-48618. This vulnerability affects Node.js **26.x** and **24.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'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published:

Updated: 2026-10-23T16:15:05.773Z

Reserved: 2026-10-05T15:00:00.729Z

Link: CVE-2026-105483

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-23T17:17:19.573

Modified: 2026-10-23T17:17:19.573

Link: CVE-2026-105483

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-23T17:30:17Z

Weaknesses