Hadithcore
Hadith #2104220

Narrated 'Umar (RA):

The Prophet (ﷺ) said: "There is no (prostrations of) forgetfulness for one who is led (in prayer) by an Imam, but when the Imam forgets, both should then make prostrations due to forgetfulness." [al-Bazzar and al-Baihaqi reported it through a weak chain of narrators].

وَعَنْ عُمَرَ رَضِيَ اَللَّهُ عَنِ النَّبِيِّ ‏- صلى الله عليه وسلم ‏-قَالَ : { لَيْسَ عَلَى مَنْ خَلَفَ اَلْإِمَامَ سَهْوٌ فَإِنْ سَهَا اَلْإِمَامُ فَعَلَيْهِ وَعَلَى مَنْ خَلْفَهُ" } رَوَاهُ اَلْبَزَّارُ وَالْبَيْهَقِيُّ بِسَنَدٍ ضَعِيفٍ .‏ [1]‏

References2 variants
Sunnah.com reference
Book 2, Hadith 239
Arabic/English book reference
Book 2, Hadith 333