---
cve: "CVE-2026-21636"
severity: "MEDIUM"
cvss: 5.8
epss: "0.9%"
vendor: "nodejs"
kev: false
exploited: false
published: "2026-01-20 21:16:05"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T20:06:55+02:00"
---

# CVE-2026-21636

> 5.8 MEDIUM

## Beschreibung

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-Vektor

```
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Verändert | bad |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Keine | good |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- 00d6cd83927d6d5c8fe9d0cdd101daa6df4b1a15 (Commit)

## Referenzen

- <https://nodejs.org/en/blog/vulnerability/december-2025-security-releases>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-21636) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_