CVE-2026-103255: n8n path traversal in Supabase node

CVE-2026-103255 · Severity: critical · CVSS 9 · Published 2026-10-01

n8n is a workflow automation platform that allows users to connect and orchestrate different applications and services. A path traversal vulnerability in the Supabase integration node allows attackers to bypass security controls and gain unauthorized access to sensitive data and APIs. By crafting malicious workflows with untrusted input, attackers can read, modify, or delete data stored in Supabase without proper authorization.

Technologies: N8n. Vendors: N8n.

Quick answers

Is CVE-2026-103255 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-103255 being exploited in the wild.
How severe is CVE-2026-103255?
Critical severity, with a CVSS score of 9, published 1 October 2026.
Which products and versions are affected?
N8n before 1.123.80, 2.0.0 before 2.39.6, 2.40.0 before 2.40.1.
Is there a fix for CVE-2026-103255?
Yes: fixed in 1.123.80, 2.39.6, 2.40.1. Until then: Restrict n8n instance access to fully trusted users only; audit all workflows using the Supabase node to ensure the table name parameter is not bound to expressions referencing external or untrusted input; disable the Supabase node by adding n8n-nodes-base.supabase to the NODES_EXCLUDE environment variable if not required; rotate the Supabase serviceRole key for any instance where vulnerable workflow configurations may have been exposed.</anigation> <parameter name="timeline">[{"kind":"disclosed","at":"2026-09-16"},{"kind":"advisory","at":"2026-10-01"}] Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-103255 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-103255?
Check whether you run N8n at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • Fixed in: 1.123.80, 2.39.6, 2.40.1

Restrict n8n instance access to fully trusted users only; audit all workflows using the Supabase node to ensure the table name parameter is not bound to expressions referencing external or untrusted input; disable the Supabase node by adding n8n-nodes-base.supabase to the NODES_EXCLUDE environment variable if not required; rotate the Supabase serviceRole key for any instance where vulnerable workflow configurations may have been exposed.</anigation> <parameter name="timeline">[{"kind":"disclosed","at":"2026-09-16"},{"kind":"advisory","at":"2026-10-01"}]

Technical details

The Supabase node in n8n inserts the tableId parameter directly into request paths without validation; since the parameter accepts expressions, it can be bound to untrusted user input. An attacker can use path traversal sequences to reach Supabase Auth and Storage APIs while carrying the administrative serviceRole key, bypassing Row Level Security and enabling unauthorized operations across all five row operation types. The vulnerability requires a workflow to bind tableId to external or untrusted input, but no special privileges or user interaction are needed to trigger the exploit.

Affected products

  • n8n n8n before 1.123.80, 2.0.0 before 2.39.6, 2.40.0 before 2.40.1

References

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