CVE-2026-71403

A flaw was found in Rancher Manager. The /v3/users update path did not enforce immutability of a User resource's username and principalIds fields. A user holding the update verb on users.management.cattle.io could inject a foreign identity provider principal into any account, so that the next login by the owner of that principal was bound to the victim's account and inherited its role bindings.

This issue affects Rancher: before 2.15.1.