n8n: SSRF Protection Bypass via MCP Client Node

## Impact On an n8n instance with SSRF protection enabled, the MCP Client node sent requests to a user-supplied endpoint without routing them through that protection and without pinning the resolved address. An authenticated user who could create or edit a workflow could therefore cause the server to connect to internal or otherwise blocked hosts and read the responses back through the workflow, exposing internal services the SSRF protection was meant to protect. ## Patches The issue has been fixed in n8n versions 2.31.5 and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict n8n instance access to fully trusted users only. - Disable the MCP Client node by adding it to the `NODES_EXCLUDE` environment variable. - Restrict network egress from the n8n host to block access to internal and link-local address ranges at the network level. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Source published

22 Jul 2026 22:07:04 UTC

Source modified

12 Aug 2026 04:26:18 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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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_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:L

Publisher rating · MODERATE