vulnerability / NVI-00017654 / Revision 1
n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments
GitHub lists this reviewed advisory for n8n-mcp. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
9.9 critical
GitHub source severity; exploitability and local consequence require separate evidence.
As of · GitHub Advisory Database
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
n8n-mcp
source listed<= 2.56.0
## 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
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-j6r7-6fhx-77wx ↗
GitHub Advisory Database · vendor advisory
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Public revision history
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- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.