CVE-2026-42282 n8n-MCP: Sensitive MCP tool-call arguments logged on authenticated requests in HTTP mode
Authenticated attackers can expose sensitive credentials and API keys in server logs when using HTTP transport mode in n8n-MCP.
- 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-2026-42282?
CVE-2026-42282 is a medium-severity vulnerability in czlonkowski n8n-mcp, published on 8 May 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 version 2.47.13, when n8n-mcp runs in HTTP transport mode, authenticated MCP tools/call requests had their full arguments and JSON-RPC params written to server logs by the request dispatcher and several sibling code paths before any redaction. When a tool call carries credential material — most notably n8n_manage_credentials.data — the raw values can be persisted in logs. In deployments where logs are collected, forwarded to external systems, or viewable outside the request trust boundary (shared log storage, SIEM pipelines, support/ops access), this can result in disclosure of: bearer tokens and OAuth credentials sent through n8n_manage_credentials, per-tenant API keys and webhook auth headers embedded in tool arguments, arbitrary secret-bearing payloads passed to any MCP tool. The issue requires authentication (AUTH_TOKEN accepted by the server), so unauthenticated callers cannot trigger it; the runtime exposure is also reduced by an existing console-silencing layer in HTTP mode, but that layer is fragile and the values are still constructed and passed into the logger. This issue has been patched in version 2.47.13.
Weakness: CWE-532
Which versions are affected by CVE-2026-42282?
2 open source packages ship an affected version, including n8n-mcp. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
n8n-mcp npm | All versions | 2.47.13 |
n8n-mcp npm | All versions | 2.47.13 |
Products include N8n-Mcp N8n-Mcp.
How do I fix CVE-2026-42282?
Upgrade n8n-mcp to 2.47.13 or later.
Is CVE-2026-42282 being exploited?
There is no known exploitation of CVE-2026-42282 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-wg4g-395p-mqv3.