How severe is CVE-2026-42282?

CVE-2026-42282 has a CVSS score of 4.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-42282?

CVE-2026-42282 affects the following packages: n8n-mcp (npm). Ecosystems affected: npm.

How do I fix CVE-2026-42282?

Update n8n-mcp to 2.47.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42282 is resolved across your whole dependency graph.

How do I detect CVE-2026-42282 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-2026-42282 if there is no patch (or I can't update yet)?

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.

Is CVE-2026-42282 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-42282 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-2026-42282?

CVE-2026-42282 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 17th 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-2026-42282?

CVE-2026-42282 is classified as CWE-532 (CWE-532). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-42282 published, and has it been updated?

CVE-2026-42282 was published on May 8, 2026 and was last updated on October 28, 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

MEDIUM severity

CVE-2026-42282 — n8n-mcp

MEDIUMFix: czlonkowski/n8n-mcp@59b665b

CVE-2026-42282 is a medium-severity (CVSS 4.3) CWE-532 vulnerability in n8n-mcp. A fix is available for n8n-mcp — see the affected versions and patch details below.

n8n-MCP: Sensitive MCP tool-call arguments logged on authenticated requests in HTTP mode

Also known asGHSA-wg4g-395p-mqv3

Published

May 8, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 5, 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-2026-42282.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

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

50Kdownloads / week

Description

Impact

When n8n-mcp runs in HTTP transport mode, authenticated MCP tools/call requests had their full arguments and JSON-RPC params written to server logs by the request dispatcher and several sibling code paths before any redaction. When a tool call carries credential material — most notably n8n_manage_credentials.data — the raw values can be persisted in logs.

In deployments where logs are collected, forwarded to external systems, or viewable outside the request trust boundary (shared log storage, SIEM pipelines, support/ops access), this can result in disclosure of:

bearer tokens and OAuth credentials sent through n8n_manage_credentials
per-tenant API keys and webhook auth headers embedded in tool arguments
arbitrary secret-bearing payloads passed to any MCP tool

The issue requires authentication (AUTH_TOKEN accepted by the server), so unauthenticated callers cannot trigger it; the runtime exposure is also reduced by an existing console-silencing layer in HTTP mode, but that layer is fragile and the values are still constructed and passed into the logger. The fix removes the leak at the source.

Impact category: CWE-532 (Insertion of Sensitive Information into Log File). CVSS 3.1 score: 4.3 Medium (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N).

Affected

Deployments running n8n-mcp v2.47.12 or earlier in HTTP transport mode (MCP_MODE=http). The stdio transport short-circuits the relevant log calls and is not affected in practice.

Patched

v2.47.13 and later.

npm: npx n8n-mcp@latest (or pin to >= 2.47.13)
Docker: docker pull ghcr.io/czlonkowski/n8n-mcp:latest

The patch routes tool-call arguments through a metadata-only summarizer (summarizeToolCallArgs) that records type, top-level key names, and approximate size — never values. The same pattern was adopted earlier for HTTP request bodies in GHSA-pfm2-2mhg-8wpx.

Workarounds

If developers cannot upgrade immediately:

Restrict access to the HTTP port (firewall, reverse proxy, or VPN) so only trusted clients can authenticate.
Restrict access to server logs (no shared SIEM ingestion, no support read-only access) until the upgrade lands.
Switch to stdio transport (MCP_MODE=stdio, the default for CLI invocation), which has no HTTP surface and short-circuits the affected log calls.

Credit

n8n-MCP thanks @Mirr2 (Organization / Jormungandr) for reporting this issue.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`n8n-mcp`	all versions	2.47.13`npm install n8n-mcp@2.47.13`

Affected Products

1 product · 1 configurations

Application

n8n-mcpn8n-mcp

< 2.47.13

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 2.47.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42282 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.

Frequently Asked Questions

### Impact When `n8n-mcp` runs in HTTP transport mode, authenticated MCP `tools/call` requests had their full arguments and JSON-RPC params written to server logs by the request dispatcher and several sibling code paths before any redaction. When a tool call carries credential material — most notably `n8n_manage_credentials.data` — the raw values can be persisted in logs. In deployments where logs are collected, forwarded to external systems, or viewable outside the request trust boundary (shared log storage, SIEM pipelines, support/ops access), this can result in disclosure of: - bearer to