n8n before versions 1.123.61, 2.27.4, and 2.28.1 contains a permission bypass vulnerability in external secrets handling caused by a mismatch between the static validation check and the runtime expression engine. An authenticated user with credential create or update permissions but without the externalSecret:list scope can embed external secret references into credentials in forms the static validation does not detect; these references resolve at workflow execution time, exposing secret values the user is not authorized to access. This issue only affects instances where an external secrets provider is configured and Advanced Permissions are in use.

n8n before version 2.10.0 contains an input validation vulnerability in the Guardrail node that allows attackers to bypass default guardrail instructions. End users can craft malicious inputs to circumvent guardrail protections and compromise workflow integrity.

n8n contains an authentication bypass in the Chat Trigger node when configured with n8n User Auth (a non-default configuration). In affected releases — before 1.123.22, the 2.0.0 through 2.9.2 line, and 2.10.0 — the authentication check on the Chat Trigger webhook endpoint can be circumvented, allowing access without valid credentials. Fixed in 1.123.22, 2.9.3, and 2.10.1.

n8n before 2.28.0 (and before 1.123.58 on the 1.x branch) contains a disk space exhaustion vulnerability in the data-table file upload endpoint. The per-request quota check does not account for files already written to the shared temporary directory, allowing an authenticated user to repeatedly upload files that accumulate on disk until the periodic cleanup runs, potentially exhausting available disk space on the host.

n8n before 1.123.24, 2.10.4, and 2.12.0 (across its 1.x and 2.x branches) contains cross-site scripting and open redirect vulnerabilities in the Form Node due to unsanitized HTML description fields and overly permissive iframe sandbox policies. Authenticated users with workflow creation permissions can inject malicious scripts or redirect parameters to perform stored XSS attacks or phishing redirects against end users.

n8n is an open source workflow automation platform. Prior to 1.123.61, 2.27.4, and, 2.28.1, an authenticated user with the default workflow:create permission could pollute Object.prototype through a crafted workflow saved, updated, or imported via the workflow API, allowing unauthenticated requests to be treated as a privileged user and exposing user and project listing endpoints. This issue is fixed in versions 1.123.61, 2.27.4, and 2.28.1.

n8n is an open source workflow automation platform. Prior to 2.27.4 and 2.28.1, the AI Agents feature did not enforce the Allowed HTTP Request Domains restriction configured on credentials when an MCP tool was pointed at an arbitrary URL, allowing a member-level user with use-only access to a shared credential to send its secret to an external server they control. This issue is fixed in versions 2.27.4 and 2.28.1.

n8n is an open source workflow automation platform. Prior to 1.123.61, 2.27.4, and, 2.28.1, an authenticated member with use-only editor access to a shared workflow could read credential-populated headers exposed via the $request object inside an HTTP Request node's pagination expression and exfiltrate the secret through item data. This issue is fixed in versions 1.123.61, 2.27.4, and 2.28.1.

n8n is an open source workflow automation platform. Prior to 2.27.4 and from 2.28.0 prior to 2.28.1, n8n instances configured with more than one trusted token-exchange issuer resolved external identities to local accounts using only the JWT sub claim and ignored the iss claim, allowing an attacker with a valid token from one trusted issuer and a sub matching a victim under another issuer to authenticate as that victim. This issue is fixed in versions 2.27.4 and 2.28.1.

n8n before 2.25.7 and 2.26.x before 2.26.2 contains an authorization bypass in the Public API execution retry endpoint, which authorizes access using the workflow:read scope instead of workflow:execute. An authenticated user with read-only access to a shared workflow can use the Public API to retry executions of that workflow, bypassing the intended permission boundary between read and execute access. This affects instances where workflows are shared with other users or across projects.