N.J. Stat. Ann. § 2A:50-48

If, at the time of the commencement of a proceeding to foreclose a mortgage for the nonpayment of interest under authority of section 2A:50-40 of this title, or the nonpayment of an installment of the principal sum due upon the mortgage under authority of section 2A:50-43 of this title, there are any municipal liens upon the mortgaged premises due and unpaid, the holder of the mortgage may pay such lien or liens and secure a judgment, not only for the unpaid interest or defaulted portion of the principal sum, but also for the amount of the municipal lien or liens by him paid, together with interest thereon from the date of the payment thereof.