Section 1102(a) gives either spouse the management and control of community real property, and then imposes the limit that matters: both spouses, personally or by a duly authorised agent, are required to join in executing any instrument by which community real property or an interest in it is leased for longer than a year, or is sold, conveyed or encumbered. Day-to-day management is single-handed; disposing of or borrowing against the home is not.
"Encumbered" is the word that catches people. A mortgage, a deed of trust, a home equity line, a judgment lien voluntarily created — each is an encumbrance, so a spouse who borrows against the house alone has acted outside the section. Subdivision (b) excludes transactions between the spouses themselves, and subdivision (e) preserves a spouse's ability to encumber their own interest under § 2033 to pay reasonable attorney's fees to retain counsel in a dissolution, nullity or legal separation proceeding.
The section then protects the outside world, which is why acting quickly matters. Subdivision (c)(2) presumes valid the sole lease, contract, mortgage or deed of a spouse holding record title, given to a lessee, purchaser or encumbrancer in good faith without knowledge of the marriage relation. And subdivision (d) sets a hard limit: an action to avoid such an instrument affecting property standing of record in one spouse's name alone may not be commenced after one year from the date the instrument was filed for record in the county recorder's office. A spouse who discovers the transaction late may be outside that period and left with a claim against the other spouse under § 1101 rather than against the property. That is a distinction with large consequences and a reason to take the paperwork to a family lawyer immediately.