Unidata ended support for all TDS versions prior to 5.x on August 31st, 2022. We will no longer be providing support for TDS 4.6.x in any capacity, including security upgrades. All TDS users are encouraged to upgrade to the latest release of TDS 5, which can be obtained from our downloads page.
For help upgrading to version 5, please refer to the documentation. To get help with issues or report bugs in version 5, contact support-thredds@unidata.ucar.edu or open an issue on our GitHub repository.