CVE-2026-21636: Node.js

Critical severity, CVSS 10.0. EPSS: 0.9% chance of exploitation in the next 30 days.

A flaw in Node.js's permission model allows Unix Domain Socket (UDS) connections to bypass network restrictions when `--permission` is enabled. Even without `--allow-net`, attacker-controlled inputs (such as URLs or socketPath options) can connect to arbitrary local sockets via net, tls, or undici/fetch. This breaks the intended security boundary of the permission model and enables access to privileged local services, potentially leading to privilege escalation, data exposure, or local code execution. * The issue affects users of the Node.js permission model on version v25. In the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase.

Affected products

• Node.js Node.js: from 25.0.0, before 25.3.0 (fixed in 25.3.0)

Published 2026-01-20. Last modified 2026-06-17.