Vulkan 1.0.4 is now the latest version of this new, high-performance graphics API. Vulkan 1.0.4 has a number of editorial fixes to the documentations, adds VL_KHR_mirror_clamp_to_edge extension to core API branch, various fixes, a few renames, updates to the XML schema, and other changes.
All of the details on the Vulkan 1.0.4 changes can be found via this GitHub change. Vulkan 1.0.4 is the first (albeit minor) update since Vulkan 1.0 (v1.0.3) was released earlier this month. Vulkan 1.0.4 saw six of its fixes done by the community, according to The Khronos Group, as part of their new GitHub-driven process for the specification.