Seems that all 6-2 and 7 versions are affected
A vulnerability allows remote authenticated users to execute arbitrary commands via a susceptible version of DiskStation Manager (DSM).https://www.synology.com/en-global/security/advisory/Synology_SA_22_03
Found this info on https://www.computerbase.de/2022-02/synology-nas-sicherheitsluecke-erlaubt-beliebige-code-ausfuehrung/ (german)
For my "real" Synology I had to manually download 6.2.4-25556-5 as it was not yet shown in interface