How severe is CVE-2026-45707?

CVE-2026-45707 has a CVSS score of 8.1/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-45707?

CVE-2026-45707 affects the following packages: n8n-mcp (npm). Ecosystems affected: npm.

How do I fix CVE-2026-45707?

Update n8n-mcp to 2.51.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45707 is resolved across your whole dependency graph.

How do I detect CVE-2026-45707 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n-mcp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-45707 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-45707 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-45707 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-45707?

CVE-2026-45707 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 33th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-45707?

CVE-2026-45707 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-45707 published, and has it been updated?

CVE-2026-45707 was published on May 29, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

HIGH severity

CVE-2026-45707 — n8n-mcp

HIGHFix: czlonkowski/n8n-mcp@853015d

CVE-2026-45707 is a high-severity (CVSS 8.1) CWE-284 vulnerability in n8n-mcp. A fix is available for n8n-mcp — see the affected versions and patch details below.

n8n-MCP: Multi-tenant MCP requests fall back to process-level n8n credentials when tenant headers are absent or incomplete

Also known asGHSA-jxx9-px88-pj69

Published

May 29, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 30, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

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 CVE-2026-45707.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk+0.18%

Lower risk than most CVEs33th percentile — riskier than 33% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-45707 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 380,526 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

1 pkg affected

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.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

n8n-mcpnpm

115Kdownloads / week

Description

Summary

When ENABLE_MULTI_TENANT=true, the HTTP transport documents that the target n8n instance is selected per-request from x-n8n-url / x-n8n-key headers. Requests that omitted those headers — or supplied only one of them — silently fell back to the process-level N8N_API_URL / N8N_API_KEY credentials configured for the operator's own n8n instance. As a result, an authenticated MCP tenant could cause n8n management calls to execute against the operator's instance instead of its own.

This affects HTTP-mode deployments of n8n-mcp that are run as a shared multi-tenant service. Single-tenant deployments (ENABLE_MULTI_TENANT unset or false) are not affected.

Impact

An authenticated MCP tenant exploiting this path could read and write workflows, executions, data-table contents, and credential metadata on the operator's n8n instance. If the operator's n8n permits Code-node execution that reaches OS-level modules, the path could escalate to remote code execution inside the operator's n8n runtime. The process-level N8N_API_KEY is, in practice, a high-privilege key — Community Edition keys are unscoped by default, and even Enterprise scopes were configured for the operator's own needs and would carry over wholesale to a tenant who triggered the fallback.

Patches

Fixed in n8n-mcp 2.51.2. The fix:

Rejects header-less multi-tenant requests at the HTTP edge with HTTP 400 / JSON-RPC -32602 before any handler runs.
Refuses to construct an env-credential n8n API client when ENABLE_MULTI_TENANT=true.
Closes secondary leak paths in trigger handlers and in the responses of n8n_health_check, n8n_diagnostic, n8n_deploy_template, and n8n_audit_instance so the operator's URL and env-key indicator are not surfaced to tenants.

Single-tenant behavior is unchanged.

Upgrade

# NPM
npx n8n-mcp@latest

# Docker
docker pull ghcr.io/czlonkowski/n8n-mcp:latest

Workarounds

If an immediate upgrade is not possible, any one of the following reduces or eliminates exposure:

Disable multi-tenant mode. Set ENABLE_MULTI_TENANT=false (or unset it) and run a separate n8n-mcp instance per tenant with that tenant's own N8N_API_URL / N8N_API_KEY. This removes the affected code path entirely.
Reject malformed requests at a proxy. Require both x-n8n-url and x-n8n-key headers on every request and return 400 if either is missing. Neutralizes the primary header-omission path but does not address the secondary response-shape disclosures, so this is a partial mitigation only.
Reduce the blast radius of the operator API key. If your n8n instance supports API key scoping (Enterprise, or a Community Edition build that exposes scopes), provision the operator's N8N_API_KEY with the minimum scopes required for the operator's own n8n-mcp functions. This does not close the boundary break but limits what a falling-back tenant can do.

Credit

Reported by @u-ktdi.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`n8n-mcp`	all versions	2.51.2`npm install n8n-mcp@2.51.2`

Affected Products

1 product · 1 configurations

Application

n8n-mcpn8n-mcp

< 2.51.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n-mcp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update n8n-mcp to 2.51.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45707 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

## Summary When `ENABLE_MULTI_TENANT=true`, the HTTP transport documents that the target n8n instance is selected per-request from `x-n8n-url` / `x-n8n-key` headers. Requests that omitted those headers — or supplied only one of them — silently fell back to the process-level `N8N_API_URL` / `N8N_API_KEY` credentials configured for the operator's own n8n instance. As a result, an authenticated MCP tenant could cause n8n management calls to execute against the operator's instance instead of its own. This affects HTTP-mode deployments of `n8n-mcp` that are run as a shared multi-tenant service. S