Ask Shaykh YQ - Episode 02 - When is Backbiting Allowed

Shaykh Yasir Qadhi delves into the technicalities of permissibility of backbiting.

Imam An Nawawi mentions some exceptions when backbiting is allowed:

When somebody has done Zulm on you.
When we need to warn the community against a general Maslaha.
If somebody comes to you for a personal advice for a greater good.