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 2.8.0 contains a cross-site scripting vulnerability in the credential management flow where authenticated users can inject malicious JavaScript URLs into OAuth2 credential Authorization URL fields. Attackers can craft malicious credentials and trick victims into clicking the OAuth authorization button, executing arbitrary scripts in their browser session with the victim's privileges.

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 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 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 1.123.25 (1.x) and before 2.11.2 (2.x), with the fix also included in 2.12.0, contains a stored cross-site scripting vulnerability in the Form Trigger node's CSS sanitization that allows authenticated users to inject malicious scripts. Attackers with workflow creation permissions can inject XSS payloads that execute persistently for all form visitors, enabling form hijacking and phishing attacks.

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.

n8n is an open source workflow automation platform. Prior to 2.25.7 and 2.26.2, an authenticated user with permission to create or modify workflows could pollute the sandbox used by the Merge node's SQL Query mode. Because the sandbox context was cached and reused across all workflow executions on the instance, prototype mutations introduced by one user's workflow persist into subsequent Merge SQL executions belonging to other users or projects. This allowed a low-privileged attacker to intercept workflow data processed by other users on the same instance. This issue only affects multi-user n8n instances where more than one user has permission to create and execute workflows containing the Merge node in SQL Query mode. This vulnerability is fixed in 2.25.7 and 2.26.2.

n8n is an open source workflow automation platform. Prior to 2.24.0, an authenticated user with permission to create or modify workflows could achieve global prototype pollution via the Microsoft SQL node by supplying a crafted value as the table parameter. This pollutes Object.prototype process-wide for the lifetime of the n8n server process, causing application-wide validation failures and rendering the n8n instance completely non-functional until restarted. This vulnerability is fixed in 2.24.0.