Executive brief
n8n is a workflow automation and data integration platform used by organizations to automate repetitive tasks and connect systems. An authenticated user can bypass quota checks on file uploads and repeatedly upload files to the data-table endpoint, causing temporary files to accumulate on disk until cleanup runs. This can exhaust available disk space and cause service disruptions or complete unavailability.
Technical details
The vulnerability is a resource exhaustion flaw (CWE-770) in n8n's data-table file upload endpoint. The root cause is that the per-request quota validation does not track cumulative disk usage in the shared temporary directory—it only checks individual request size limits. An authenticated user (authentication is required) can exploit this via the network by sending repeated file upload requests, each bypassing the quota check individually, causing temporary files to accumulate. The attacker can achieve denial of service by exhausting available disk space, triggering service failures or outages. Patches are available in versions 2.28.0 and 1.123.58 or later. Temporary mitigations include restricting instance access, lowering uploadMaxFileSize configuration, and monitoring temporary directory disk usage.
Affected products
- n8n n8n < 2.28.0 and < 1.123.58 (1.x branch)
Timeline
- 2026-06-24: disclosed
- 2026: patched: Patched in versions 2.28.0 and 1.123.58