GHSA-j6r7-6fhx-77wx
CRITICALGHSA-j6r7-6fhx-77wx is a critical-severity (CVSS 9.9) CWE-639 vulnerability in n8n-mcp. O3 Security confirms whether GHSA-j6r7-6fhx-77wx is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
n8n-MCP: Cross-tenant access to workflow version backups in multi-tenant HTTP deployments
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-j6r7-6fhx-77wx.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-j6r7-6fhx-77wx plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 366,357 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
n8n-mcpnpmDescription
Impact
In multi-tenant HTTP deployments — where a single n8n-mcp server serves several tenants — the locally stored workflow version history (the automatic backups taken before workflow updates) was not isolated per tenant. An authenticated tenant could read workflow version snapshots belonging to other tenants, and could delete or destroy other tenants' stored backups.
A stored snapshot includes full node definitions, so the exposed data can contain credential references and authorization headers configured on nodes. This is therefore a confidentiality issue in addition to an integrity/availability one.
Affected configurations
- HTTP mode with multi-tenancy enabled (
ENABLE_MULTI_TENANT=true), where multiple tenants are served by a single shared instance and database.
Not affected:
- stdio / single-user deployments (e.g. Claude Desktop).
- Single-tenant HTTP deployments (one tenant per instance and database).
Affected versions
<= 2.56.0
Patched version
2.56.1. The stored version history is now isolated per instance, so a tenant can only access its own backups. Upgrading runs a one-time migration that isolates existing history and clears previously stored, un-scoped backups (these are auto-created, short-retention backups).
Workarounds
If users cannot upgrade immediately:
- Disable the workflow version tool by setting
DISABLED_TOOLS=n8n_workflow_versionsin the server environment (for example, in your Docker.env). This removes the affected tool from the deployment for all tenants; automatic backups are unaffected, but the cross-tenant access path is closed. - Alternatively, do not run in multi-tenant mode — serve each tenant from a separate instance with its own database, so no local store is shared between tenants.
- Restrict network access to the HTTP endpoint to trusted operators.
stdio and single-tenant HTTP deployments are not affected.
Credit
Reported by Francisco Rosales (@0xmagic0) and coordinated by Ax Sharma (@axsharma) of Manifold Security.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n-mcp | all versions | 2.56.1 |
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 2.56.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-j6r7-6fhx-77wx 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 GHSA-j6r7-6fhx-77wx 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 GHSA-j6r7-6fhx-77wx. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-j6r7-6fhx-77wx in your dependencies?
O3 detects GHSA-j6r7-6fhx-77wx across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.