Sealant compositions comprising a colloidally stabilized latex and methods of using the same to service a wellbore are provided. The sealant compositions may include: an aliphatic conjugated diene monomer; an additional monomer comprising a non-aromatic unsaturated mono- or di-carboxylic ester monomer, an aromatic unsaturated monomer, a nitrogen-containing monomer, or combinations thereof; and a protective colloid. The foregoing sealant composition may be displaced into the wellbore to isolate the subterranean formation from a portion of the wellbore, to support a conduit in the wellbore, to plug a void or crack in the conduit, to plug a void or crack in a cement sheath disposed in an annulus of the wellbore, to plug an opening between the cement sheath and the conduit, or combinations thereof. The colloidally stabilized latex remains substantially stable when exposed to salt, which may be present in the wellbore and/or in the sealant composition itself.