Vulnerability · Published Sep 8, 2026 · Assigned by GitHub_M

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

High 8.7

In plain English

A high-severity resource allocation without limits in n8n from n8n-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High

Exploit odds (30 days)0.6%top 50.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	n8n	2.38.2	GHSA-hh89-3r9w-qj3j
npm	n8n	2.37.7	GHSA-hh89-3r9w-qj3j

Affected products (as reported)

Vendor	Product	Versions
n8n-io	n8n	< 2.37.7>= 2.38.0, < 2.38.2

Weakness: CWE-770 · 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

References

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