Overview:
A user attempts to run the following Call:
GET https://{dns}/api/{version}/objects/users/{id}/permissions
The user receives the following error:
"INSUFFICIENT_ACCESS",
"message": "User does not have sufficient privileges to perform the action"
Root Cause:
A user has the ability to run the following Call:
GET https://{dns}/api/{version}/objects/users/me/permissions
When attempting to retrieve permissions for a different user other than themselves, the initial user requires additional permissions.
Solution:
To run the described API Call, the user must have the Users Read, Security Profiles Read, and Permission Sets Read Admin Permissions in the Security Profile/Permission Set.