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.
History

Wed, 21 Jan 2026 19:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-284
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 21 Jan 2026 12:15:00 +0000

Type Values Removed Values Added
Title nodejs: Nodejs network segmentation bypass
Weaknesses CWE-281
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N'}

threat_severity

Moderate


Wed, 21 Jan 2026 11:30:00 +0000

Type Values Removed Values Added
First Time appeared Nodejs
Nodejs nodejs
Vendors & Products Nodejs
Nodejs nodejs

Tue, 20 Jan 2026 20:45:00 +0000

Type Values Removed Values Added
Description 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.
References
Metrics cvssV3_0

{'score': 5.8, 'vector': 'CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: hackerone

Published: 2026-01-20T20:41:55.700Z

Updated: 2026-01-21T18:52:53.133Z

Reserved: 2026-01-01T15:00:02.339Z

Link: CVE-2026-21636

cve-icon Vulnrichment

Updated: 2026-01-21T18:40:15.504Z

cve-icon NVD

Status : Received

Published: 2026-01-20T21:16:05.813

Modified: 2026-01-21T19:16:05.560

Link: CVE-2026-21636

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-01-20T20:41:55Z

Links: CVE-2026-21636 - Bugzilla