Neb. Rev. Stat. §§ 77-1923
Where any county shall have commenced proceedings in this state under the provisions of section 77-2039, C.S.Supp.,1941, and shall have purchased real estate sold under said proceedings, as trustee for the benefit of the governmental bodies interested in the taxes, and the sale has been confirmed and the deed or deeds therefor have been issued and delivered to the county and the county has sold the real estate prior to May 26, 1943, any person, persons, firm or corporation or governmental body of the state, which shall have or has had any interest whatsoever in said real estate, lien thereon or interest in said taxes, shall have one year and no more, under any circumstances whatever, from May 26, 1943, within which to bring any action whatsoever to attack said proceeding, any of the steps taken thereunder, the method of purchasing, the power of the county either to bring said proceeding or to purchase the property in its name as trustee or said deeds. In the event no such action shall be brought within said period so fixed by this period of limitation, then the title of the purchaser from the county shall be valid and absolute against any such person, persons, firm or corporation or governmental body.
Neb. Rev. Stat. §§ 77-1923