Is it permissible to suffice with reciting Al-Fatiha in the second rak'ah without reciting a surah after it due to forgetfulness, then perform the prostration of forgetfulness (sujud al-sahw) before the salutation (tasleem)?

The worshiper is not at fault and is not required to perform the prostration of forgetfulness (sujood as-sahw) if he omits reciting surahs after Al-Fatiha, because reciting surahs is sunnah (recommended) and not Wajib (obligatory), and the prayer is valid in this case.