{"id":"CVE-2026-55608","aliases":["GHSA-2cf7-hpwf-47h9"],"title":"n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode","summary":"n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode","severity":"medium","cvss":4.2,"cwe":["CWE-200","CWE-863"],"vendor":"n8n-mcp","product":"n8n-mcp","ecosystem":"npm","affected":["n8n-mcp <= 2.57.3"],"patched":["n8n-mcp 2.57.4"],"published":"2026-07-14","updated":"2026-07-14","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-2cf7-hpwf-47h9","references":[{"url":"https://github.com/czlonkowski/n8n-mcp/security/advisories/GHSA-2cf7-hpwf-47h9"},{"url":"https://github.com/czlonkowski/n8n-mcp/commit/c1ca1e73697feaec5ec2a5fb7e6992a2892b62c9"},{"url":"https://github.com/czlonkowski/n8n-mcp/releases/tag/v2.57.4"},{"url":"https://github.com/advisories/GHSA-2cf7-hpwf-47h9"}],"tags":["ghsa","npm"],"ingestedAt":"2026-07-14T20:39:11.129Z","epss":0.0028,"epssPercentile":0.20789,"slug":"CVE-2026-55608","body":"## Overview\n\n## Summary\n\nIn multi-tenant HTTP mode (`ENABLE_MULTI_TENANT=true`), an authenticated tenant could, under certain conditions, reach n8n-mcp's local default-scope `workflow_versions` backups instead of being confined to its own tenant scope. This affects n8n-mcp's own local workflow-version storage, not a normal n8n API capability.\n\n## Impact\n\nAn authenticated MCP HTTP tenant could read or delete workflow-version backups stored in the default (single-tenant) scope — for example backups left from a prior single-tenant deployment or a migration period. Workflow snapshots may contain sensitive workflow configuration depending on their contents. Single-tenant and stdio deployments are not affected.\n\n## Affected versions\n\n`<= 2.57.3`\n\n## Patched version\n\n`2.57.4`\n\n## Remediation\n\nUpgrade to n8n-mcp `2.57.4` or later. The fix requires a complete tenant context in multi-tenant mode and fails closed for workflow-version access that cannot be attributed to a specific tenant.\n\n## Workarounds\n\n- Restrict network access to the HTTP endpoint (firewall / reverse proxy / VPN) so only trusted callers can reach it.\n- Run in stdio mode, which has no multi-tenant HTTP surface.\n- If default-scope backups from a prior single-tenant deployment are not needed, removing them eliminates the exposure.\n\n## Credit\n\nReported by @DavidCarliez.\n\n## Affected packages\n\n- `n8n-mcp <= 2.57.3`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `n8n-mcp 2.57.4`","depth":"sunlit","depthScore":23,"depthScoreParts":{"impact":23.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}