CVE-2026-65594

Published Jul 22, 2026

Last updated 6 days ago

Overview

Description
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.
Source
disclosure@vulncheck.com
NVD status
Analyzed
Products
n8n

Risk scores

CVSS 4.0

Type
Secondary
Base score
5.1
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Severity
MEDIUM

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
3.6
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Severity
MEDIUM

Weaknesses

disclosure@vulncheck.com
CWE-863

Social media

Hype score
Not currently trending

Configurations