n8n before 2.34.1 and 2.33.4 contains an authorization bypass in the custom project role deletion (reassignment) path. When deleting a custom project role with a reassignment target, the code validated only that the target role existed and was project-scoped, performing no project-level authorization check. A user holding only the narrow role:manageProject global scope could delete any custom project role in use on the instance and reassign its holders (including themselves) to the built-in project:admin role, gaining full administrative control of projects they had no legitimate access to.
Published: 2026-08-20
Updated: 2026-09-01
Base Score: 9
Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C
Severity: High
Base Score: 8.8
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity: High
Base Score: 7.4
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:L/VA:L/SC:H/SI:H/SA:H
Severity: High
EPSS: 0.00228