ESXi Patch or Express Patches are released with KB articles unlike traditional release notes. Below are the release KB for the ESXi 5.5 Express Patch 11
VMware ESXi 5.5, Patch ESXi550-201703401-SG: Updates esx-base (2149577) | VMware KB
VMware ESXi 5.5, Patch Release ESXi550-201703001 (2149576) | VMware KB
Thanks,
MS