CVE-2026-55608 n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode
Authenticated tenants can access or delete other tenants' workflow backups in multi-tenant mode due to incorrect authorization checks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-55608?
CVE-2026-55608 is a medium-severity missing authorization vulnerability in czlonkowski n8n-mcp, published on 15 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
n8n-MCP is an MCP server that provides AI assistants access to n8n node documentation, properties, and operations. Prior to 2.57.4, multi-tenant HTTP mode with ENABLE_MULTI_TENANT=true could allow an authenticated tenant to access default-scope workflow_versions backups instead of being confined to the tenant scope, exposing or deleting workflow-version backups from prior single-tenant deployments or migrations. This issue is fixed in version 2.57.4.
Which versions are affected by CVE-2026-55608?
2 open source packages ship an affected version, including n8n-mcp. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
n8n-mcp npm | All versions | 2.57.4 |
n8n-mcp npm | All versions | 2.57.4 |
Products include N8n-Mcp N8n-Mcp.
How do I fix CVE-2026-55608?
Upgrade n8n-mcp to 2.57.4 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-55608 being exploited?
There is no known exploitation of CVE-2026-55608 in the wild and no public exploit code.
Other vulnerabilities in czlonkowski n8n-mcp
- CVE-2026-54052 n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments
- CVE-2026-42449 n8n-MCP: IPv4-mapped IPv6 addresses bypass SSRF protection in validateUrlSync(), enabling full SSRF for SDK embedders
- CVE-2026-39974 n8n-MCP has an Authenticated SSRF via instance-URL header in multi-tenant HTTP mode
- CVE-2026-45707 n8n-MCP: Multi-tenant MCP requests fall back to process-level n8n credentials when tenant headers are absent or incomplete
- CVE-2026-44694 n8n-MCP: Authenticated SSRF in n8n-mcp webhook and API client paths
Sources
Also known as GHSA-2cf7-hpwf-47h9.