n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments
Impact
In multi-tenant HTTP deployments — where a single n8n-mcp server serves several tenants — the locally stored workflow version history (the automatic backups taken before workflow updates) was not isolated per tenant. An authenticated tenant could read workflow version snapshots belonging to other tenants, and could delete or destroy other tenants' stored backups.
A stored snapshot includes full node definitions, so the exposed data can contain credential references and authorization headers configured on nodes. This is therefore a confidentiality issue in addition to an integrity/availability one.
Affected configurations
- HTTP mode with multi-tenancy enabled (
ENABLE_MULTI_TENANT=true), where multiple tenants are served by a single shared instance and database.
Not affected:
- stdio / single-user deployments (e.g. Claude Desktop).
- Single-tenant HTTP deployments (one tenant per instance and database).
Affected versions
<= 2.56.0
Patched version
2.56.1. The stored version history is now isolated per instance, so a tenant can only access its own backups. Upgrading runs a one-time migration that isolates existing history and clears previously stored, un-scoped backups (these are auto-created, short-retention backups).
Workarounds
If users cannot upgrade immediately:
- Disable the workflow version tool by setting
DISABLED_TOOLS=n8n_workflow_versionsin the server environment (for example, in your Docker.env). This removes the affected tool from the deployment for all tenants; automatic backups are unaffected, but the cross-tenant access path is closed. - Alternatively, do not run in multi-tenant mode — serve each tenant from a separate instance with its own database, so no local store is shared between tenants.
- Restrict network access to the HTTP endpoint to trusted operators.
stdio and single-tenant HTTP deployments are not affected.
Credit
Reported by Francisco Rosales (@0xmagic0) and coordinated by Ax Sharma (@axsharma) of Manifold Security.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | n8n-mcp | < 2.56.1 | 2.56.1 |
References
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L- Weakness (CWE)
CWE-639, CWE-862- Platform
- npm
- Package
n8n-mcp- Disclosed
- 14.07.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-j6r7-6fhx-77wx - CC BY 4.0
Vulnerability history: n8n-mcp
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 11
- First → latest
- 04.2026 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 1
- High 6
- Medium 4
Disclosures per year
- 2026: 11
-
n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.