CVE-2026-106072

MEDIUM

6.7

CVSS Score

Published: October 23, 2026 at 04:15 PM UTC

Updated: October 23, 2026 at 07:42 PM UTC

1 product affected across 1 vendorNode.js

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Severity

MEDIUM6.7

Exploit prediction

EPSS 0.6%

Description

A flaw in Node.js TLS hostname verification allows a certificate with only a DNS SAN to authenticate an IP endpoint when the client connects using a non-canonical IPv4 spelling, such as `0177.0.0.1`, `0x7f.0.0.1`, `2130706433` or `127.1`. `tls.checkServerIdentity()` did not classify these hosts as IP addresses, but normalized them to their canonical form and matched the result against the certificate DNS names. A certificate containing `DNS:127.0.0.1` and no `IP Address:127.0.0.1` SAN was therefore accepted, while the same certificate is correctly rejected for `127.0.0.1`. Exploitation requires a certificate with a numeric DNS SAN issued by a CA trusted by the client, and a platform resolver that accepts these spellings, such as glibc. This vulnerability affects Node.js **26.x**, **24.x**, and **22.x**.