CVE-2026-55608
MEDIUMCVE-2026-55608 is a medium-severity (CVSS 4.2) Information Exposure vulnerability in n8n-mcp. O3 Security confirms whether CVE-2026-55608 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
n8n-MCP: Incorrect authorization can expose default-scope workflow version backups in multi-tenant HTTP mode
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
n8n-mcpnpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n-mcp | all versions | 2.57.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n-mcp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update n8n-mcp to 2.57.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55608 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55608 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55608. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55608 in your dependencies?
O3 detects CVE-2026-55608 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.