Cal. Sts. & Hy. Code § 6571
Any action, suit, or proceeding attacking or contesting the validity of any deed issued under the provisions of this division, or the validity of the proceedings subsequent to the issuance of the certificate of sale, shall be brought within 12 months after the issuance of the deed, and if the validity of the deed or of the proceedings is not contested within that 12 months' period, it shall not be thereafter contested or questioned in any action, suit, or proceeding, except that an action, suit, or proceeding with respect to any deed of owner-occupied residential property may be brought within 12 months after discovery of the issuance of the deed or, for owner-occupied residential property sold between January 1, 1969, and January 1, 1979, within 12 months after the enactment of the amendments to this section made during the 1981-82 Regular Session of the Legislature.
A defense to a proceeding pursuant to this section shall be that the current owner of record is a bona fide purchaser for value.
The Legislature finds and declares that the court of appeal in Atkins v. Kessler, 97 Cal. App. 3d 784, held that under the former provisions of this division the statute of limitations in this section could not be raised against an owner in possession of residential real property during the entire period of delinquency and sale because due process was violated. It is therefore the intent of the Legislature that the amendments to this section made during the 1981-82 Regular Session of the Legislature shall be applied retrospectively with respect to any owners in possession of residential real property during the entire period of delinquency and at the time of the sale whose homes were sold pursuant to this act between January 1, 1969, and January 1, 1979.
Ca. Sts. and High. Code § 6571