n8n before 1.123.67, 2.31.5, and 2.32.1 contains a prototype pollution vulnerability in the Edit Fields (Set) node. The node assigns output fields via a dot-notation path setter without restricting the field name, allowing an authenticated user to name a field after an inherited built-in method path and corrupt a shared global in the main Node.js process. Because that global is used on the request-authentication path, the instance then fails every authenticated request, causing an instance-wide denial of service for all users until the process is restarted.

n8n before 1.123.67, 2.x before 2.31.5, and 2.32.x before 2.32.1 contain a type confusion vulnerability in the Send Email node, which does not enforce that its message fields are strings. A crafted non-string value supplied from a workflow expression into the text or HTML body field can be interpreted by the underlying mail library (Nodemailer) as a file path or URL, allowing arbitrary local file disclosure and server-side request forgery (SSRF). Exploitation requires a pre-existing active workflow with an unauthenticated webhook, valid SMTP credentials configured on the node, and untrusted input mapped directly into the body field; this is not a default configuration.

n8n before 2.31.5 and before 2.32.1 contain a sandbox escape vulnerability in expression evaluation. An authenticated user with permission to create or modify workflows can craft expressions using arrow-function bodies to bypass the expression sandbox, triggering system command execution on the host running n8n. The issue is fixed in versions 2.31.5 and 2.32.1.

n8n before 1.123.67, 2.31.5, and 2.32.1 contains a credential authorization bypass in the HTTP Request node. An authenticated member with edit access to a shared workflow can reference another user's credential while specifying the credential type via an expression. Because the pre-execution permission check compares the unresolved expression instead of the resolved credential type, the ownership check is skipped and the credential is loaded at execution time, allowing the member to use or exfiltrate a credential they were not granted. Exploitation requires knowing the target credential's identifier.

n8n before 1.123.67, 2.31.5, and 2.32.1 validates credential-access only for a node's top-level credentials and not for credentials referenced inside an Execute Sub-workflow node's inline workflow JSON. A member with Editor access to a shared workflow (when workflow sharing is enabled) who knows a target credential's ID can reference that credential in the inline JSON; it passes save-time and runtime validation and resolves in the parent workflow's project context, allowing the attacker to use or exfiltrate credentials they are not permitted to access.

n8n before 1.123.64, 2.29.8, and 2.30.1 fails to enforce the "Allowed HTTP Request Domains" restriction on HTTP-based credentials (Header Auth, Basic Auth, Query Auth, OAuth) in the GraphQL node, unlike the HTTP Request node. An authenticated user able to create or edit workflows can point the node's endpoint at a server they control and exfiltrate restricted credentials. Only instances where a credential has "Allowed HTTP Request Domains" configured and is usable by non-owner users are affected.

n8n before 2.29.8 and 2.30.x before 2.30.1 (affected from 2.27.0, when the OAuth 2.1 consent and token-issuance flow was introduced) does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger workflow configured with n8n OAuth2 authentication, a member-level user can register an OAuth client, self-approve consent for another user's workflow, and obtain a valid token. The workflow then runs in the owner's project context with the owner's stored credentials, and the attacker can set tool inputs and read outputs (potentially including data from the owner's connected integrations), breaking user and project isolation.

n8n before 2.30.1 and 2.29.8 assigns all Public API key scopes to JWTs issued through the Token Exchange module regardless of the acting user's role. On instances where the Token Exchange feature and Public API are enabled, a low-privileged user who can obtain a valid external JWT trusted by a configured issuer can use the resulting access token to invoke administrator-only Public API operations such as role escalation, user creation, and user deletion (role escalation requires an Advanced Permissions license), and, when unverified Community Package installation is enabled, achieve remote code execution.

n8n before 1.123.64, 2.29.8, and 2.30.1 contains a TOCTOU race condition in the Git node's clone operation that allows authenticated users to bypass path restrictions by swapping a directory for a symlink after the path is validated but before the clone runs. This lets an attacker plant a crafted repository in the community node directory, which n8n loads as a custom node on the next restart, executing arbitrary JavaScript on the server. Both self-hosted and cloud instances are affected.

n8n before 1.123.64, 2.x before 2.29.8, and before 2.30.1 contains a DOM-based cross-site scripting vulnerability in the HTML preview, which renders execution output into an iframe srcdoc without the sandbox attribute. A sanitizer bypass allows injected script to execute same-origin as the editor. When a victim opens the preview, the script can call authenticated APIs using the victim's session. An account with global:member privileges can exploit the issue.