CVE-2026-103257 Overview
CVE-2026-103257 is a path traversal vulnerability [CWE-22] in the n8n workflow automation platform. The flaw resides in the n8n node, which fails to validate resource identifiers before using them in internal API calls. Attackers can craft malicious resource IDs to redirect requests to unintended resources. Successful exploitation grants unauthorized access to workflows, executions, and credential secrets scoped to the compromised API key. The vulnerability affects n8n versions before 1.123.80, 2.0.0 through versions before 2.39.6, and 2.40.0 before 2.40.1.
Critical Impact
Attackers with a valid API key can traverse resource boundaries to read workflows, execution logs, and stored credential secrets outside the key's intended scope.
Affected Products
- n8n versions before 1.123.80
- n8n versions from 2.0.0 before 2.39.6
- n8n versions from 2.40.0 before 2.40.1
Discovery Timeline
- 2026-10-01 - CVE-2026-103257 published to the National Vulnerability Database (NVD)
- 2026-10-01 - Last updated in NVD database
Technical Details for CVE-2026-103257
Vulnerability Analysis
The vulnerability stems from insufficient validation of resource identifiers passed to the n8n node. The node accepts resource IDs from API callers and uses them to construct downstream API requests without enforcing scope or path boundaries. Attackers submit crafted identifiers containing traversal sequences or references to resources outside their authorized set. The backend then resolves these identifiers against internal routes and returns data the caller should not be able to reach. This exposes workflows, execution history, and credential secrets accessible within the authenticating API key's scope.
Root Cause
The root cause is missing input validation on resource identifiers used in internal routing. The n8n node treats caller-supplied IDs as trusted path components rather than opaque, scope-bound tokens. Without canonicalization and authorization checks tied to the requesting identity, traversal payloads reach resource lookup logic unchallenged.
Attack Vector
The attack vector is network-accessible and requires no user interaction, though exploitation presumes the attacker holds or can supply an API key accepted by the target instance. An attacker invokes the n8n node with a resource ID that references objects outside the intended scope. The server dispatches the API call against the redirected path, returning sensitive data in the response. Because credential secrets are among the exposed resources, exploitation can lead to lateral movement into systems integrated with the n8n workflow.
No verified public proof-of-concept code is available. See the GitHub Security Advisory GHSA-89p4-6h98-c7xm and the VulnCheck Advisory for n8n Path Traversal for upstream technical detail.
Detection Methods for CVE-2026-103257
Indicators of Compromise
- Unexpected API requests invoking the n8n node with resource ID parameters containing traversal characters, encoded slashes, or references to IDs outside the caller's normal activity.
- Audit log entries showing an API key accessing workflows, executions, or credentials it has not previously touched.
- Spikes in credential retrieval or workflow export events correlated to a single API key.
Detection Strategies
- Review n8n audit and HTTP access logs for n8n node invocations where the resource identifier does not match the expected format or scope.
- Alert on API responses that return credential or workflow payloads to callers whose historical pattern does not include those resources.
- Correlate n8n API key usage with downstream service authentications to identify credential replay following suspected exfiltration.
Monitoring Recommendations
- Enable verbose request logging on the n8n API gateway, retaining caller identity, resource IDs, and response sizes.
- Forward n8n logs to a centralized SIEM and build detections for anomalous resource access per API key.
- Monitor outbound connections from n8n workers for use of credentials shortly after suspicious API activity.
How to Mitigate CVE-2026-103257
Immediate Actions Required
- Upgrade n8n to 1.123.80, 2.39.6, or 2.40.1 or later, depending on the deployed major version branch.
- Rotate all credentials and API keys stored in or issued by affected n8n instances, since prior exposure cannot be ruled out.
- Audit workflows, executions, and credential access logs for the period preceding the upgrade.
Patch Information
Fixes are available in n8n versions 1.123.80, 2.39.6, and 2.40.1. Refer to the GitHub Security Advisory GHSA-89p4-6h98-c7xm for the authoritative patch details and release notes.
Workarounds
- Restrict network access to the n8n API to trusted administrative networks until patching completes.
- Reduce the scope of issued API keys and revoke keys that are not actively required.
- Disable or restrict use of the n8n node within workflows where feasible until upgrades are deployed.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
