Overview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Alpine Linux 3.23 , Alpine Linux 3.24 , Debian 10 , Debian 11 , Debian 12 , Debian 13 , EL 10 , EL 6 , EL 7 , EL 8 , EL 9 , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 18.04 , Ubuntu 20.04 , Ubuntu 22.04 , Ubuntu 24.04 , Ubuntu 26.04
- Affected packages:
- nodejs @ 16.20.2 (+110 more)