CVE-2026-2035366

A flaw was found in OpenStack Keystone where an application credential token can escape its intended project scope through token-method reauthentication. Keystone rejects an explicit scope change for an application credential token, but an omitted scope falls through to the owner's default project. If the owner has roles on that default project, Keystone issues a new token scoped there while still carrying the original application credential identity. Custom Keystone authentication plugins are subject to the same incomplete rescope guard. This allows a limited-scope application credential for one project to access another project within the owner's role assignments.