Is it permissible to despise one of the Companions without exiting the fold of Islam, while possibly exiting the fold of faith?

Hostility towards the Companions of the Prophet (peace be upon him) and disparaging them is a sign of abandonment and lack of divine success from Allah, for they are the ones who supported and spread the religion, and transmitted the Quran and the Sunnah. Allah chose them to accompany His Prophet.

No one hates them except a hypocrite, and loving them is an act of religion, faith, and righteousness. Hating them is disbelief, hypocrisy, and transgression.

Whoever hates the Companions has hated the religion, and whoever disparages any of them, know that he is a heretic.

As for one who curses them with a curse that does not impugn their justice or their religion, such as describing some of them as stingy or cowardly, he deserves disciplinary action and chastisement, but is not ruled to be a disbeliever.

However, as for one who claims that they apostatized after the Messenger of Allah except for a small number, or that the majority of them became فاسق (sinful/transgressors), there is no doubt in his disbelief, because this is a lie, contrary to what the Quran states regarding Allah's satisfaction with them and His praise for them.

In general, among the categories of those who curse, some are undoubtedly disbelievers, some are not ruled to be disbelievers, and for some, there is hesitation.

Cursing all the Companions is disbelief. If one curses a single Companion specifically for being a Companion, it is disbelief. However, if one curses him for a personal and worldly matter, it does not necessitate declaring him a disbeliever. Nevertheless, if one hates any of them due to his companionship, it is undoubtedly disbelief.