n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.56.1, in HTTP mode with multi-tenancy enabled through ENABLE_MULTI_TENANT=true, n8n-mcp's local workflow version history backups were not isolated per tenant, allowing an authenticated tenant to read workflow version snapshots belonging to other tenants and delete or destroy other tenants' stored backups, including full node definitions, credential references, and authorization headers. This issue is fixed in version 2.56.1.

Source published

15 Jul 2026 20:34:10 UTC

Source modified

18 Jul 2026 02:18:02 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.56.1, in HTTP mode with multi-tenancy enabled through ENABLE_MULTI_TENANT=true, n8n-mcp's local workflow version history backups were not isolated per tenant, allowing an authenticated tenant to read workflow version snapshots belonging to other tenants and delete or destroy other tenants' stored backups, including full node definitions, credential references, and authorization headers. This issue is fixed in version 2.56.1.

Source published

15 Jul 2026 21:16:54 UTC

Source modified

24 Oct 2026 21:10:00 UTC

Observed here

25 Oct 2026 13:17:22 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · [email protected] · Secondary · 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

CVSS 3.1 · [email protected] · Primary · 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

## 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_versions` in 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.

Source published

14 Jul 2026 19:07:14 UTC

Source modified

14 Jul 2026 19:31:05 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L

Publisher rating · CRITICAL