CVE-2026-103248 in n8n
Summary
by MITRE • 10/01/2026
n8n versions before 1.123.80, from 2.0.0 before 2.39.6, and from 2.40.0 before 2.40.1 contain a filter injection vulnerability in the Supabase node's Filters (String) mode that fails to escape field values. Attackers can inject filter expressions from untrusted input to read all table rows, update all records, or delete entire tables in a single request.
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Analysis
by VulDB Data Team • 10/02/2026
The n8n automation platform contains a critical security flaw within its Supabase integration node, specifically affecting versions prior to 1.123.80, the range from 2.0.0 up to but not including 2.39.6, and the sequence from 2.40.0 through 2.40.1. This vulnerability manifests as a filter injection weakness located in the Filters String mode of the Supabase node configuration interface. The core technical deficiency lies in the failure of the application to properly escape or sanitize field values when constructing database queries based on user-supplied input. Instead of treating these inputs strictly as data parameters, the system processes them directly within the logic that builds filter expressions for interacting with the Supabase backend service. This lack of proper input validation allows an attacker who controls the workflow configuration or can influence the input fields to inject arbitrary code into the query structure.
From a technical perspective, this flaw aligns closely with CWE-94, which describes Improper Control of Generation of Code (Code Injection), and more specifically CWE-73, External Control of File Name or Path if it leads to unauthorized access, though in this context, it is primarily an injection into query logic. The vulnerability enables attackers to manipulate the underlying SQL-like filter syntax used by Supabase. By injecting malicious expressions through untrusted input fields, an adversary can bypass intended filtering constraints and execute commands that affect data integrity and availability. This type of attack vector is consistent with techniques observed in ATT&CK framework sub-techniques related to Data Manipulation via Injection or Unauthorized Access to Resources, where the attacker leverages trusted application logic to perform actions outside its normal operational parameters.
The operational impact of this vulnerability is severe due to the high privileges typically associated with database integration nodes in automation workflows. An authenticated user who can configure such a workflow has the ability to read all rows from any table accessible by the connected Supabase service, effectively leading to a complete data exfiltration scenario. Furthermore, the attacker can update existing records across entire tables or delete them entirely in a single request. This capability transforms what might seem like a configuration error into a catastrophic risk for organizations relying on n8n for critical business processes involving sensitive database operations. The ability to wipe out entire tables represents a significant threat to data availability and integrity, potentially causing service disruptions and loss of historical records that are difficult or impossible to recover without robust backup systems.
Mitigation strategies must focus primarily on immediate version upgrades as the primary defense mechanism. Organizations running affected versions should upgrade n8n to at least 1.123.80 for legacy users, 2.39.6 for those in the second range, or preferably 2.40.1 and later releases where this filter injection vulnerability has been addressed by properly escaping field values during query construction. In addition to upgrading software, administrators should enforce strict least-privilege principles when configuring database connections within n8n workflows. This involves ensuring that service accounts used for Supabase integrations do not possess unnecessary write or delete permissions unless absolutely required for specific business logic. Implementing input validation at the application level and auditing workflow configurations regularly can further reduce the risk of exploitation by limiting the surface area available to potential attackers seeking to inject malicious filter expressions.