n8n: Unauthenticated Persistent Storage Exhaustion via OAuth Dynamic Client Registration Endpoint
Impact
The OAuth Dynamic Client Registration endpoints validated field sizes only for redirect_uris, leaving client_name and grant_types bounded by presence checks alone. An unauthenticated remote caller could submit arbitrarily large values in either field and have them persisted to the database. Repeated registration therefore grew persistent storage without limit and without any account on the instance. The patch caps client_name at its column length and limits grant_types to the grant types the server actually implements, with the array capped at that count.
Patches
The issue has been fixed in n8n versions 2.37.7 and 2.38.2. Users should upgrade to one of these versions or later to remediate the vulnerability.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Restrict network access to the n8n instance so that only trusted clients can reach it.
- Place the instance behind a reverse proxy configured to enforce strict request body size limits below the default 16 MiB.
- Monitor database size for unexpected growth and audit the
oauth_clientstable for anomalous entries.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Software afectado
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| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Paquete de npm | n8n | >= 2.38.0, < 2.38.2, < 2.37.7 | 2.38.2, 2.37.7 |
Referencias
- Vector CVSS
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N- Debilidad (CWE)
CWE-770- Plataforma
- npm
- Paquete
n8n- Publicada
- 10.09.2026
- Actualizado
- 11.10.2026 10:22
Fuentes y licencias
OSV / GitHub Advisory Database - GHSA-hh89-3r9w-qj3j - CC BY 4.0
Historial de vulnerabilidades: n8n
Todas las vulnerabilidades publicadas de este paquete (Paquete de npm), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 156
- Primera → última
- 05.2023 09.2026
- Sin corrección
- 1
- Explotada en ataques
- 1
Distribución por gravedad
- Crítica 24
- Alta 58
- Media 74
Divulgaciones por año
- 2023: 3
- 2024: 0
- 2025: 14
- 2026: 139
-
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