Abstract. Let (R, m, k) be an excellent local ring of equal characteristic. Let j be a positive integer such that H i m (R) has finite length for every 0 ≤ i < j. We prove that if R is F -injective in characteristic p > 0 or Du Bois in characteristic 0, then the truncated dualizing complex τ >−j ω q R is quasi-isomorphic to a complex of k-vector spaces. As a consequence, Finjective or Du Bois singularities with isolated non-Cohen-Macaulay locus are Buchsbaum. Moreover, when R has F -rational or rational singularities on the punctured spectrum, we obtain stronger results generalizing [Ma15] and [Ish84].