Sony released firmware updates to patch exploits. If you plan to use homebrew or backups:
Updates usually come as:
While I cannot provide direct download links, here is where the community discusses PS Vita ROMs VPK UPD safely: ps vita roms vpk upd
Recommendation: Stop downloading random .vpk files from Google Drive. Use PKGj on your Vita. It handles the UPD (updates) and DLC automatically. Sony released firmware updates to patch exploits