New York Consolidated Laws, Real Property Tax Law - RPT § 1137. Statute of limitations

Every deed given pursuant to the provisions of this article shall be presumptive evidence that the proceeding and all proceedings therein and all proceedings prior thereto from and including the assessment of the real property affected and all notices required by law were regular and in accordance with all provisions of law relating thereto.  After two years from the date of the recording of such deed, the presumption shall be conclusive.  No proceeding to set aside such deed may be maintained unless the proceeding is commenced and a notice of pendency of the proceeding is filed in the office of the proper county clerk prior to the time that the presumption becomes conclusive.