CVE-2026-106069

About vulnerability

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.

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 (+115 more)