CVE-2026-65594
AWAITING NVDn8n before 2.29.8 and 2.30.x before 2.30.1 (affected from 2.27.0, when the OAuth 2.1 consent and token-issuance flow was introduced) does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger...
Full CISO analysis pending enrichment.
What systems are affected?
| Package | Ecosystem | Vulnerable Range | Patched |
|---|---|---|---|
| n8n | npm | — | No patch |
Do you use n8n? You're affected.
How severe is it?
What should I do?
No patch available
Monitor for updates. Consider compensating controls or temporary mitigations.
Which compliance frameworks are affected?
Compliance analysis pending. Sign in for full compliance mapping when available.
Frequently Asked Questions
What is CVE-2026-65594?
n8n before 2.29.8 and 2.30.x before 2.30.1 (affected from 2.27.0, when the OAuth 2.1 consent and token-issuance flow was introduced) does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger workflow configured with n8n OAuth2 authentication, a member-level user can register an OAuth client, self-approve consent for another user's workflow, and obtain a valid token. The workflow then runs in the owner's project context with the owner's stored credentials, and the attacker can set tool inputs and read outputs (potentially including data from the owner's connected integrations), breaking user and project isolation.
Is CVE-2026-65594 actively exploited?
No confirmed active exploitation of CVE-2026-65594 has been reported, but organizations should still patch proactively.
How to fix CVE-2026-65594?
No patch is currently available. Monitor vendor advisories for updates.
What is the CVSS score for CVE-2026-65594?
No CVSS score has been assigned yet.
What are the technical details?
Original Advisory
n8n before 2.29.8 and 2.30.x before 2.30.1 (affected from 2.27.0, when the OAuth 2.1 consent and token-issuance flow was introduced) does not verify that the authenticated user has access to the workflow referenced as the OAuth resource. On instances with at least one active MCP Server Trigger workflow configured with n8n OAuth2 authentication, a member-level user can register an OAuth client, self-approve consent for another user's workflow, and obtain a valid token. The workflow then runs in the owner's project context with the owner's stored credentials, and the attacker can set tool inputs and read outputs (potentially including data from the owner's connected integrations), breaking user and project isolation.
Weaknesses (CWE)
CWE-863 — Incorrect Authorization: The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
- [Architecture and Design] Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- [Architecture and Design] Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
Source: MITRE CWE corpus.
References
- github.com/n8n-io/n8n/security/advisories/GHSA-q5xf-xhwf-cwqf vendor-advisory
- vulncheck.com/advisories/n8n-before-missing-oauth-authorization-check third-party-advisory
Timeline
Related Vulnerabilities
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Same package: n8n CVE-2026-27495 9.9 n8n: Code Injection enables RCE
Same package: n8n CVE-2026-27577 9.9 n8n: Code Injection enables RCE
Same package: n8n