PT-2026-88506 · Git+3 · N8N
CVE-2026-86075
·
Published
2026-09-08
·
Updated
2026-09-10
CVSS v4.0
8.7
High
| Vector | AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
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.
Exploit
Fix
Allocation of Resources Without Limits
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Weakness Enumeration
Related Identifiers
Affected Products
N8N