n8n before 2.28.0 contains an improper authorization vulnerability allowing authenticated users to assign workflows to folders in other projects. Attackers can bypass project and folder authorization boundaries by supplying crafted request payloads during workflow creation, causing logical integrity violations in target project folder structures.

n8n before 1.123.55, 2.25.7, and 2.26.2 contains an authorization vulnerability in three mutating evaluation test-run endpoints that authorize state-changing actions using the workflow:read scope instead of the action-appropriate workflow:execute scope. On instances using Advanced Permissions (Enterprise/Cloud) with projects and viewer roles, an authenticated user with the project:viewer role can start new evaluation test runs, cancel in-flight runs, and delete run records for workflows they only have read access to.

n8n before 1.123.55, 2.25.7, and 2.26.2 contains an authorization bypass in the POST /workflows/{workflowId}/test-runs/new endpoint, which authorizes access using the workflow:read scope instead of workflow:execute. An authenticated user with read-only access to a workflow can trigger a real evaluation test run, causing the workflow to execute via the internal workflow runner and resulting in unintended outbound API calls, data mutations, or other side effects in connected downstream systems. The issue primarily affects instances using the Evaluations feature where RBAC project roles grant workflow:read without workflow:execute.

n8n before 1.123.61, 2.x before 2.27.4, and 2.28.x before 2.28.1 contains a SQL injection vulnerability in the legacy MySQL v1 node's executeQuery operation. The operation substitutes evaluated {{ ... }} expression values directly into the raw SQL string without parameterization. When a workflow uses this operation with expression-sourced values and is connected to an externally-reachable trigger (such as a Webhook node), attacker-controlled input reaching those expressions results in SQL injection, allowing execution of arbitrary SQL with the configured MySQL credentials' privileges. The MySQL v2 node, which uses parameterized queries, is not affected.

n8n before versions 1.123.18 and 2.6.2 fails to verify HMAC-SHA256 signatures on Zendesk webhooks in the ZendeskTrigger node. Attackers who know the webhook URL can send unsigned POST requests to trigger workflows with arbitrary malicious data.

The Execute Command node in n8n allows authenticated users to execute arbitrary commands on the host system where n8n runs. Attackers with user access or compromised credentials can exploit this node to run malicious commands, potentially leading to data exfiltration, service disruption, or complete system compromise.

n8n before 2.25.7 and 2.26.x before 2.26.2 contains an abstract syntax tree (AST) security validator bypass in the Python Code node. An authenticated user with permission to create or modify workflows containing a Python Code node can bypass the validator and access the task executor module namespace. The issue only affects self-hosted instances where the Python Task Runner is enabled; where N8N_BLOCK_RUNNER_ENV_ACCESS is configured to allow it, this can disclose environment variables accessible to the task runner process.

n8n contains a stored cross-site scripting vulnerability in the Chat Trigger node's Custom CSS field due to a misconfiguration of the sanitize-html library. Affected releases are those before 1.123.27, the 2.0.0 through 2.13.2 line, and 2.14.0 (fixed in 1.123.27, 2.13.3, and 2.14.1). An authenticated user with permission to create or modify workflows can inject JavaScript that bypasses sanitization, resulting in stored XSS against any user who visits the public chat page.

n8n before 2.8.0 contains an authentication bypass vulnerability allowing authenticated SSO users to disable SSO enforcement through the API. Attackers can create local password credentials to authenticate directly, bypassing organizational SSO policies and identity-provider-enforced multi-factor authentication.

n8n before version 2.4.0 contains a sql injection vulnerability in MySQL, PostgreSQL, and Microsoft SQL nodes that allows authenticated users to inject arbitrary SQL through unescaped identifier values in node configuration parameters. Attackers with workflow creation permissions can supply specially crafted table or column names to execute unauthorized database commands and compromise data integrity.