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 die ihr glaubt, meidet viel von den Mutmaßungen; gewiß, manche Mutmaßung ist Sünde. Und sucht nicht (andere) auszukundschaften und führt nicht üble Nachrede übereinander. Möchte denn einer von euch gern das Fleisch seines Bruders, wenn er tot sei, essen? Es wäre euch doch zuwider. Fürchtet Allah. Gewiß, Allah ist Reue-Annehmend und Barmherzig.
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.
