n8n Elasticsearch/ElasticSecurity Node Path Injection via Unencoded Identifiers

Technical Analysis

The nodes constructed Elasticsearch REST endpoint URLs by directly interpolating user- or workflow-provided identifiers (index/document names) into the path without URL-encoding or normalization checks. An identifier containing path separators or dot-segment sequences (e.g. '../') could cause the resulting request to resolve to a different index or to a cluster-level administrative endpoint rather than the intended document path. Because these nodes act as tool-layer connectors executing under a stored, often highly privileged Elasticsearch credential, this misdirection effectively grants an attacker-controlled input the ability to escalate scope from document-level operations to cluster administration actions. The entry point is any workflow field that accepts externally influenced index/document identifiers (e.g., from webhook input, API responses, or chained agent/tool output), making this a classic confused-deputy pattern within an automation/agent-tool integration.

Affected Systems

n8n

Detection Signatures

• Workflow logs showing Elasticsearch/ElasticSecurity node requests with path segments containing '../', '..%2F', or unencoded '/' in index/document identifier fields
• Unexpected Elasticsearch API calls to cluster admin endpoints (e.g., _cluster, _cat) originating from document-level node operations
• Identifier fields in n8n workflows populated from external/untrusted input (webhooks, HTTP responses, user forms) without sanitization
• Requests reaching indices other than those explicitly configured in the workflow

Remediation Steps

1. 1

   Upgrade n8n

   Update to n8n 1.123.76, 2.37.7, 2.38.2, or later, which encode identifiers as single URL path segments and reject values that normalize away path traversal sequences.

2. 2

   Restrict instance access

   Limit n8n instance and workflow editing access to fully trusted users until upgraded.

3. 3

   Disable affected nodes if unused

   Add n8n-nodes-base.elasticsearch and n8n-nodes-base.elasticSecurity to the NODES_EXCLUDE environment variable if these integrations are not required.

4. 4

   Audit workflows for untrusted identifier input

   Review existing workflows using these nodes to ensure index and document identifier fields do not derive from externally-controlled or unsanitized input.

5. 5

   Apply least-privilege credentials

   Scope Elasticsearch credentials used by n8n to the minimum required indices/actions to limit blast radius from any path manipulation.