CVE-2026-86075: n8n unauthenticated storage exhaustion via OAuth registration

CVE-2026-86075 · Severity: high · CVSS 7.5 · Published 2026-09-08

n8n is a popular workflow automation platform that enables users to connect and automate business processes. An unauthenticated attacker can repeatedly register OAuth clients with arbitrarily large values in certain fields, causing the database to grow without limit and potentially degrading system availability. This attack requires no credentials or authentication, allowing any remote attacker to exhaust storage resources.

Technologies: N8n, n8n (npm). Vendors: N8n, npm.

Quick answers

Is CVE-2026-86075 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-86075 being exploited in the wild.
How severe is CVE-2026-86075?
High severity, with a CVSS score of 7.5, published 8 September 2026.
Which products and versions are affected?
N8n < 2.37.7, >= 2.38.0 < 2.38.2; n8n (npm) SEMVER:introduced=2.38.0,fixed=2.38.2.
Is there a fix for CVE-2026-86075?
Yes. n8n (npm): upgrade to 2.38.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-86075 attacked?
It is attacked over the network, in a web application.
Am I affected by CVE-2026-86075?
Check whether you run N8n or n8n (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • n8n (npm): upgrade to 2.38.2 or later
    npm install n8n@2.38.2

Technical details

The OAuth Dynamic Client Registration endpoint in n8n validates only the `redirect_uris` field for size limits, leaving `client_name` and `grant_types` fields bounded only by presence checks. An unauthenticated remote attacker can submit arbitrarily large values in these fields via the registration endpoint; these values are persisted to the database without sanitization. By repeatedly calling the registration endpoint with oversized payloads, an attacker can cause uncontrolled database growth, leading to denial of service or availability degradation. The attack requires only network access to the endpoint (no authentication, privileges, or user interaction). Patches in n8n 2.37.7 and 2.38.2 cap `client_name` to column length and restrict `grant_types` to valid server grant types.

Affected products

  • n8n n8n < 2.37.7, >= 2.38.0 < 2.38.2

Identifiers

  • CVE-2026-86075
  • GHSA-hh89-3r9w-qj3j

Timeline

  • 2026-09-02: disclosed: Advisory published to GitHub Advisory Database
  • 2026: patched: Fixed in n8n versions 2.37.7 and 2.38.2

References

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