Halakhah su Salmi 12:4

All this, only if one spoke demeaningly of his friend by chance. But if (G–d forbid) he is habituated to this sin, like those who customarily sit and say: "Thus and thus did Ploni (so and so) do," "Thus and thus did his fathers do," "This and this (demeaning thing) did I hear about him" — men such as these are called by Chazal "ba'alei (men of) lashon hara," and their punishment is far greater [than that of the former]. For in their perverseness of spirit and their malice of heart they transgress the Torah of the L–rd, and it becomes hefker to them, as explained above in the end of the introduction. And about them it is said in the tradition (Psalms 12:4): "Let the L–rd cut off all smooth-talking lips, the tongue that speaks haughtily."

There is a much graver sin [than tale bearing] which is classified under this prohibition and that is slander;⁶The laws against slander do not apply when you wish to protect someone from harm. For example, if you know that someone plans to cheat in business, or that he plans to borrow money and not repay the loan, or that the person who wishes to marry someone’s daughter is a evil and corrupt man, then it is a mitzvah to inform the concerned party. (Pis’chei Teshuvah 156, also Chafeitz Chayim, Rechilus 9) which is, speaking of someone's shame, even if it is true. But a person who spreads lies [about others] is guilty of besmirching someone's name. A slanderer is a person who says, "So and so has done such and such; so and so were his parents; such and such a thing I heard about him," and he relates shameful things. Regarding such a person, Scripture states,⁷Psalms 12:4. "May Hashem cut off all smooth [talking] lips, the tongue that speaks haughty words."⁸The Gemara Yoma 9a states that the expression “haughty words” in this verse refers to lashon hara. Anyone speaking lashon hara displays haughtiness, for he places himself above God’s law. A person who accepts slanderous gossip is worse than the one who spreads it. The heavenly decree⁹Barring them from entering the Land of Israel. against our forefathers, in the wilderness was sealed, only because [they committed] the sin of slander.¹⁰The meraglim (spies) who explored the land spoke badly about it and the people accepted their slanderous report.