In RESTEasy the insecure File.createTempFile() is used in the DataSourceProvider, FileProvider and Mime4JWorkaround classes which creates temp files with insecure permissions that could be read by a local user.
https://security.netapp.com/advisory/ntap-20230427-0001/
https://github.com/resteasy/resteasy/pull/3409/commits/807d7456f2137cde8ef7c316707211bf4e542d56