High [CVE-2026-48618] Authentication bypass due to TLS hostname handling and unicode dot separator mismatch

A flaw in Node.js TLS hostname handling can cause Node.js unicode dot separator handling can lead to tls wildcard-depth authentication bypass due to resolver and verifier hostname normalization mismat. This can lead to confidentiality impact or bypass of the intended security boundary under affected configurations.

This vulnerability affects all supported release lines: **Node.js 22**, **Node.js 24**, and **Node.js 26**. A flaw was found in Node.js.

This flaw involves a mismatch in how Node.js handles TLS (Transport Layer Security) hostnames and unicode dot separators during authentication. An attacker could exploit this to bypass intended security boundaries, potentially leading to unauthorized access and confidentiality impact.

The issue affects Node.js versions 22, 24, and 26 as shipped in Red Hat products. Red Hat severity: Important — CVSS 7.7 (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N).

Weakness: CWE-289. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 10.0 Extended Update Support; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat Enterprise Linux 9.6 Extended Update Support; Red Hat Hardened Images.

Affected products named by the advisory: Red Hat package: nodejs24; Red Hat package: nodejs22.