Is cursing a mosque considered an act of disbelief, even if the person subsequently seeks forgiveness?

It is religiously forbidden to curse a mosque; indeed, the one who does so may reach the point of disbelief, because the mosque is one of the manifest symbols of Islam, and its veneration is part of the veneration of religion. Disrespecting or cursing it is considered disrespecting the symbols of religion. Allah Almighty said: "That [is so]. And whoever honors the symbols of Allah – indeed, it is from the piety of hearts," and "In houses which Allah has permitted to be raised and that His name be remembered therein." Scholars have prohibited holding judicial proceedings in mosques due to the potential for their desecration.

Similarly, it is forbidden to curse a specific Muslim. Ibn Taymiyyah stated that people of knowledge do not curse any specific Muslim, but rather employ general cursing, such as Allah Almighty's saying: "Unquestionably, the curse of Allah is upon the wrongdoers." The Prophet (peace be upon him) forbade cursing a specific man who used to drink alcohol, saying: "Do not curse him; for he loves Allah and His Messenger." It is permissible to curse those with blameworthy characteristics, such as the dissolute and image-makers. However, there is a difference of opinion regarding cursing a specific disbeliever or immoral person, and the preferred view is not to curse any specific individual whatsoever.