GHSA-VXV2-8J6R-PCPG Gitea: OAuth token introspection returns metadata of tokens issued to other clients (RFC 7662 section 4 violation)

Live reproduction against Gitea 1.26.1 Setup: Gitea 1.26.1 docker stack with two users admin and victim and two OAuth applications owned by different users: Client A: id=5dda747d-7fdd-4694-85ff-ce4f893ce51e owner=admin Client B: id=588f778f-4a41-4914-ae01-85d776c369db owner=victim admin runs an...