CVE-2026-86994: n8n: Cross-User Active Workflow ID and Lifecycle Event Disclosure via Missing userId Filter

Two paths leaked data across users. The /rest/active-workflows endpoint listed all active workflow IDs on the instance to any signed-in member, regardless of sharing. Separately, push events for workflow activation, deactivation and publication were broadcast to every connected client. Those events carried workflow IDs, version IDs and activation-error detail.

This is a missing authorization check (CWE-862), the kind where a user filter was never applied. The attacker needs a low-privilege account, such as a global:member. They need no user interaction and no special tooling: calling the endpoint or watching the push channel is enough.

The exposure is low on its own. The attacker learns which workflows exist and are active, when they change, and the text of activation errors, which can reveal node names, credentials in use or error details. The IDs do not grant access to the workflows. The risk grows on shared instances with several teams, and when the IDs are combined with another flaw that takes a workflow ID.

The patch scopes both the listing and the push events through the sharing service, so a user only sees workflows they can access.

Affected: n8n below 1.123.76, 2.0.0 up to but not including 2.37.7, and 2.38.0 up to but not including 2.38.2. Any instance with more than one user account is exposed. Check the version:

npm ls n8n

For Docker installs, check the image tag or the version in the n8n UI.

Upgrade to 1.123.76, 2.37.7 or 2.38.2, or later:

npm install -g [email protected]

The advisory lists stopgaps that it says do not fully remediate the risk:

• Limit instance access to fully trusted users.
• Do not provision global:member accounts for untrusted users until the instance is patched.

Check access logs for requests to /rest/active-workflows from accounts that have no reason to enumerate workflows, and for long-lived push connections from low-privilege users. The advisory lists no other indicators, and the leak leaves no trace in workflow data. Review the list of global:member accounts and remove any you do not recognise.

Impact

The endpoint /rest/active-workflows returned every active workflow ID on the instance to any member, regardless of sharing, and workflow activation, deactivation and publication push events were broadcast to every connected client, carrying workflow IDs, version IDs and activation-error detail across users. The patch scopes both the listing and the push events through the sharing service, so a user only sees workflows they can access.

Patches

The issue has been fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2. Users should upgrade to one of these versions or later to remediate the vulnerability.

Workarounds

If upgrading is not immediately possible, administrators should consider the following temporary mitigations:

• Restrict n8n instance access to fully trusted users only.
• Avoid provisioning global:member accounts for untrusted users until the instance is patched.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.