CVE-2026-21636 Affecting nodejs-20 package, versions <20.20.0-r0


Severity

Recommended
0.0
critical
0
10

Snyk's Security Team recommends NVD's CVSS assessment. Learn more

Threat Intelligence

EPSS
0.02% (7th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-NODEJS20-15227218
  • published5 Feb 2026
  • disclosed20 Jan 2026

Introduced: 20 Jan 2026

CVE-2026-21636  (opens in a new tab)

How to fix?

Upgrade Chainguard nodejs-20 to version 20.20.0-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nodejs-20 package and not the nodejs-20 package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1