Craft CMS is a content management system (CMS). From version 4.0.0-RC1 to before version 4.17.8 and from version 5.0.0-RC1 to before version 5.9.14, an unauthenticated user can call assets/generate-transform with a private assetId, receive a valid transform URL, and fetch transformed image bytes. The endpoint is anonymous and does not enforce per-asset authorization before returning the transform URL. This issue has been patched in versions 4.17.8 and 5.9.14.