Yes. Allah compares backbiting to eating the flesh of one's dead brother (49:12). The Prophet ﷺ explained that it is mentioning your brother in a way he dislikes.
O vous qui avez cru! Evitez de trop conjecturer [sur autrui] car une partie des conjectures est péché. Et n'espionnez pas; et ne médisez pas les uns des autres. L'un de vous aimerait-il manger la chair de son frère mort? (Non!) vous en aurez horreur. Et craignez Allah. Car Allah est Grand Accueillant au repentir, Très Miséricordieux.
Hadith
Sahih Muslim 2589
Abu Huraira reported Allah's Messenger (ﷺ) as saying:Do you know what is backbiting? They (the Companions) said: Allah and His Messenger know best. Thereupon he (the Holy Prophet) said: Backbiting implies your talking about your brother in a manner which he does not like. It was said to him: What is your opinion about this that if I actually find (that failing) in my brother which I made a mention of? He said: If (that failing) is actually found (in him) what you assert, you in fact backbited him, and if that is not in him it is a slander
This is general information, not a fatwa. For your own situation, ask a qualified scholar.
Questions about halal and haram
Is backbiting (gheebah) haram?
Yes. Allah compares backbiting to eating the flesh of one's dead brother (49:12). The Prophet ﷺ explained that it is mentioning your brother in a way he dislikes.
