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.
اى كسانى كه ايمان آورده‌ايد، از گمان فراوان بپرهيزيد. زيرا پاره‌اى از گمانها در حد گناه است. و در كارهاى پنهانى يكديگر جست و جو مكنيد. و از يكديگر غيبت مكنيد. آيا هيچ يك از شما دوست دارد كه گوشت برادر مرده خود را بخورد؟ پس آن را ناخوش خواهيد داشت. و از خدا بترسيد، زيرا خدا توبه‌پذير و مهربان است.
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.
