CVE-2026-21636

CVSS 5.8 MediumEPSS 0.0%
  • CVSS Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
  • Published: 2026-01-20T21:16:05.813

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.

Related CVE by CWE

No related CWE found.

Top CVE for Vendor

No vendor taxonomy on this entry.

Recently Exploited Similar Vulnerabilities

No recent KEV-listed items for this vendor/product.

How to fix CVE-2026-21636

CVE-2026-21636 is a medium severity vulnerability affecting the affected product.

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 […]

Exploit Difficulty: EASY
⏱️ Time to exploit: < 1 hour
🛠️ Required skills: Basic web security knowledge
💰 Public exploits: Likely available

How to Fix:

1 Identify affected systems

- Check if you're running the affected product

2 Immediate actions

- Update to the latest patched version
- If patching is not immediately possible: restrict network exposure, apply least-privilege access

3 Verification

- Test the fix in a staging environment first
- Review logs for signs of exploitation
- Monitor for IOCs (Indicators of Compromise)

4 Long-term prevention

- Enable automatic security updates
- Set up vulnerability monitoring
- Review and harden security configurations

Exploit Difficulty Assessment

EASY
⏱️ Time to Exploit: < 1 hour
🛠️ Skills Required: Basic web security knowledge
💰 Public Exploits: Likely available

Vulnerability Timeline

Jan 20, 2026
Vulnerability Published

CVE details first published to NVD database

Jan 20, 2026
Imported to Database

Added to this CVE tracking system

Detection Rules & IOCs

No specific detection rules generated for this vulnerability type.

No vendor/product data available.