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Node.Js CVE-2026-21636

CRITICAL
Improper Access Control (CWE-284)
2026-01-20 support@hackerone.com
Privilege Escalation Node.js Red Hat Node.Js Suse
Critical
Disputed · 10.0 NVD
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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Enable Node.js permission model on v25
  2. Delivery
    Supply attacker-controlled socketPath to net/tls/undici
  3. Exploit
    Bypass --permission restrictions
  4. Execution
    Connect to arbitrary Unix Domain Socket
  5. Impact
    Access privileged local services

Vulnerability Assessment

Weakness
CWE
CWE-284
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V8 - Authorization Access control enforcement
MITRE ATT&CK

1 technique across 1 tactic: Defense Evasion

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

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Exploitation Conditions

Node.js v25 running with --permission flag enabled but without --allow-net; application accepts untrusted socketPath parameters or URL inputs passed to net.connect(), tls.connect(), or fetch() operations.
Impact

CVSS 10.0 — complete bypass of network sandboxing. UDS access to Docker sockets, database sockets, and other local services effectively grants full system access.
Exploit ScenarioDerived

An attacker running code in a Node.js sandbox with --allow-net restrictions connects to the local Docker socket (/var/run/docker.sock) via UDS, gaining full container management capabilities and effectively root access to the host.
Act Now Prioritize within 24-48h. Why: CRITICAL severity.
Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Node.js has a CVSS 10.0 permission model bypass that allows Unix Domain Socket connections to completely bypass network restrictions when --allow-net is configured.

Earlier versions of this analysis (1)
v1 Mar 12, 2026 - 21:54 CVSS 10.0

Node.js permission model bypass via Unix Domain Sockets enables unrestricted network access.

RemediationAI

Update Node.js. Restrict UDS access at the OS level. Don't rely solely on Node.js permissions for security boundaries.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

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Technical ContextAI · show details

Node.js's permission model fails to restrict Unix Domain Socket (UDS) connections (CWE-284) when --allow-net is configured. Attackers can use UDS to communicate with any local service, bypassing the intended network restrictions entirely.

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  • Exploit and PoC references, threat intelligence from 22 sources
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Severity by source

Sources disagree (Medium–Critical)
NVD PRIMARY 10.0 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
SUSE 5.8 MEDIUM
AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
Red Hat 5.8 MEDIUM

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Patch released
Apr 09, 2026 - 14:30 nvd
Patch available
CVE Published
Jan 20, 2026 - 21:16 nvd
CRITICAL 10.0

DescriptionCVE.org

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.

Executive ViewAI

Why It Matters

CVE-2026-21636 presents critical security risk, a improper access control vulnerability rated CVSS 10.0. Successful exploitation could critically impact the confidentiality, integrity, and availability of affected systems. Organizations should apply vendor updates immediately when available and implement compensating controls in the interim.

Business Impact: Severe
Compensating Controls

Apply vendor patch. If immediate patching is not feasible: (1) Restrict access to affected endpoints; (2) Implement additional authorization checks; (3) Enable audit logging.

Threat Intelligence Overview

EPSS Score
0.0%
Top 95% exploitable
Data Quality
3 sources
Confidence: Low
NVD CVE.org EPSS Vendor

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity CRITICAL
CISA KEV No
Public POC No
EPSS 0.0%
Patch available Yes
Active threat No
Deciding rule
CRITICAL severity
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Out-of-Cycle
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact
Very High

Priority Score

50
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +50
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.

Affected Products (CPE)CVE.org

cpe:2.3:a:nodejs:node.js:*:*:*:*:-:*:*:*

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Same weakness CWE-284 – Improper Access Control

View all
CVE-2015-3306 CRITICAL POC
10.0
CVE-2012-4681 CRITICAL POC
9.8
CVE-2011-3544 CRITICAL POC
9.8
CVE-2012-1723 CRITICAL POC
9.8
CVE-2012-5076 CRITICAL POC
9.8
CVE-2014-3120 HIGH POC
8.1
CVE-2013-2423 LOW POC
3.7
CVE-2016-3427 CRITICAL
9.8

Same technique Privilege Escalation

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CVE-2024-0012 CRITICAL POC
9.3
CVE-2025-47812 CRITICAL POC
10.0
CVE-2013-0422 CRITICAL POC
9.8
CVE-2013-0632 CRITICAL POC
9.8
CVE-2024-9474 MEDIUM POC
6.9
CVE-2017-5689 CRITICAL POC
9.8
CVE-2021-20021 CRITICAL POC
9.8
CVE-2017-12635 CRITICAL POC
9.8

Vendor StatusVendor

SUSE

Severity: Medium
Product Status
SUSE Linux Enterprise High Performance Computing 12 Fixed
SUSE Linux Enterprise High Performance Computing 15 SP7 Fixed
SUSE Linux Enterprise Module for Web and Scripting 15 SP7 Fixed
SUSE Linux Enterprise Server 15 SP7 Fixed
SUSE Linux Enterprise Server 16.0 Fixed

References

Advisories & patches
ADVISORY https://nodejs.org/en/blog/vulnerability/december-2025-security-releases ADVISORY https://seclists.org/oss-sec/2026/q2/984

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