The Messenger of Allah ﷺ said, "Whoever does not pray the two rakahs of Fajr should pray them after the sun has risen."
حدثنا عقبة بن مكرم العمي البصري حدثنا عمرو بن عاصم حدثنا همام عن قتادة عن النضر بن أنس عن بشير بن نهيك
قال رسول الله ﷺ من لم يصل ركعتي الفجر فليصلهما بعد ما تطلع الشمس
[Its chain is daif] Ibn Khuzayma also reported it, no. 1117, through Amr bin Asim with the same chain, with the wording, "Whoever forgets the two rakahs of Fajr should pray them when the sun rises." So the hadith specifically concerns forgetfulness. Ibn Hibban graded it sahih, no. 613, as did Hakim, 1/274, saying it meets the criteria of the two Shaykhs, and Dhahabi agreed with him (!)Qatada is a well-known mudallis and he narrated it with an ambiguous form (an'ana).