CVE-2026-86996: n8n: Agent Workflow Tool Bypasses Sub-Workflow Caller Policy
Impact
A workflow's "This workflow can be called by" setting was enforced by the Execute Workflow node but was not consulted when the same workflow was attached to an Agent as a tool. A user who could build an Agent could therefore call a workflow that its owner had restricted, and read back what it returned. The patch applies the sub-workflow caller policy on the Agent tool path.
Patches
The issue has been fixed in n8n versions 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. - Audit workflows attached as Agent tools and review their caller policy settings. - Remove sensitive workflows from Agent tool configurations until the instance is patched.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Other sources
n8n is an open source workflow automation platform. Prior to 2.37.7 and 2.38.2, the workflow setting named This workflow can be called by was enforced by the Execute Workflow node but not when a workflow was attached to an Agent as a tool. A user able to build an Agent could invoke a restricted workflow and read its returned data. The affected path is packages/cli/src/modules/agents/tools/workflow-tool-factory.ts, where executeWorkflow omitted SubworkflowPolicyChecker.checkForProject. This issue is fixed in versions 2.37.7 and 2.38.2.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Configuration
Remove sensitive workflows from Agent tool configurations until the n8n instance is upgraded to a fixed version.
n8n Agent tool configurations workflow caller policy workaround (This workflow can be called by) = Remove sensitive workflows from Agent tool configurations until the instance is patched - Compensating control
Restrict n8n instance access to fully trusted users only (temporary mitigation until patched).
- Operational
Audit workflows attached as Agent tools and review their caller policy settings (temporary mitigation until patched).
Event History
Frequently Asked Questions
Who can exploit this issue?
A user who can build an Agent can exploit it by attaching a restricted workflow to that Agent as a tool. The user could then invoke the workflow and read the data it returns.
Is the restriction bypass limited to a particular workflow invocation method?
Yes. The caller policy was enforced through the Execute Workflow node, but not when the workflow was attached to an Agent as a tool.
Which versions contain the fix?
The issue is fixed in n8n versions 2.37.7 and 2.38.2. Versions prior to those releases are affected.