AOS R10.5.3 was released and posted for the NetVanta 7000 Series. R10.5.3 is a maintenance release only. It includes bug fixes found since the release of R10.5.2. It does not include any of the features available in later feature releases (R10.6.0, R10.7.0, R10.8.0, etc.). Please reference the NetVanta 7000 Series Products AOS R10.5.3.HA Release Notes for specific details. The NetVanta 7000 series firmware can be downloaded from the firmware landing page links for each product below.
UPDATE: This version was replaced by AOS R10.5.3.HA released for the NetVanta 7000 Series to address a paging group issue explained here: AOS R10.5.3 Supplemental Errata for Paging Groups in the NetVanta 7000 Series