n8n EUVD-2026-101727

Requires an authenticated user holding editor (write) permission on a shared workflow in a multi-user n8n instance. The attacker must author or modify a workflow that uses Workflow Tool or Workflow Retriever inline/nested sub-workflow definitions that reference credentials owned by another user and not accessible to the attacker; execution then runs those sub-workflows with the owner's credential values. Limiting factors: exploitation depends on the credential-sharing/RBAC model being in use, the existence of restricted credentials owned by another user, and the attacker already having editor access to a relevant shared workflow - so single-user instances or instances without shared workflows/credential scoping are not affected (AV:N, PR:L, AT:P). Fixed in n8n 1.123.83.

This is a genuine but conditional privilege/authorization issue rather than a drive-by remote threat. The CVSS 4.0 vector (AV:N/AC:L/AT:P/PR:L/UI:N) scores 7.2 (High) and confirms the attacker must already hold low-level authenticated access - specifically editor rights on a shared workflow - and that a specific attack requirement exists (AT:P), meaning exploitation is not possible against an arbitrary unauthenticated target. The vulnerable/subsequent-system impact (VC:H, SC:H/SI:H) reflects that an attacker crosses an authorization boundary to use another user's high-value credentials, so the real impact is confidentiality of restricted credentials and the systems they unlock. No EPSS score was provided in the input, so exploitation probability cannot be quantified; no CISA KEV listing and no public proof-of-concept are present, so this is 'no public exploit identified at time of analysis.' Net assessment: this matters most for multi-tenant or team n8n deployments that rely on credential-scoping/sharing as a security boundary, where a malicious or compromised editor becomes an insider threat able to abuse an owner's credentials. For single-user or trusted-team instances the practical risk is low. It should be prioritized for patching by organizations using n8n's RBAC/credential-sharing features, but it is not a widespread internet-facing worming threat.

An authenticated n8n user who has been granted editor access to a shared workflow embeds a nested Workflow Tool or Workflow Retriever inline sub-workflow that references credentials owned by another user which they are not authorized to use. When the workflow runs, n8n executes the inline sub-workflow with the owner's credential values, letting the attacker reach systems (APIs, databases, SaaS accounts) protected by those restricted credentials. No public exploit code was identified at time of analysis; the attack requires existing editor-level sharing access (PR:L, AT:P).