Mo. Rev. Stat. § 141.610
Each court administrator's or sheriff's deed given pursuant to the provisions of the land tax collection law shall be presumptive evidence that the suit and all proceedings therein and all proceedings prior thereto from and including assessment of the lands affected thereby and all notices required by law were regular and in accordance with all provisions of the law relating thereto. The court administrator or sheriff shall record its deed and shall collect said recording fee at the time of sale. After one year from the date of the court administrator's foreclosure sale, the presumption shall be conclusive pursuant to sections 141.210 to 141.810. Notwithstanding section 516.010, no suit to set aside or to attack the validity of any such court administrator's or sheriff's deed shall be commenced or maintained unless the suit is filed within one year from the date of the court administrator's foreclosure sale.
§ 141.610, RSMo