Instituto Nacional de ciberseguridad. Sección Incibe
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CVE-2026-21636

Severity CVSS v4.0:
Pending analysis
Type:
CWE-284 Improper Access Control
Publication date:
20/01/2026
Last modified:
30/01/2026

Description

A flaw in Node.js&amp;#39;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.<br /> <br /> * The issue affects users of the Node.js permission model on version v25.<br /> <br /> In the moment of this vulnerability, network permissions (`--allow-net`) are still in the experimental phase.

Impact

Vector 3.x
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 10.00 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x
10.00
Severity 3.x
CRITICAL

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:* 25.0.0 (including) 25.3.0 (excluding)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools