Via the KSA MOH Command and Control Center: MOH: '1 New Confirmed Corona Cases Recorded'. The new case is a 77-year-old Saudi woman in Buraidah, who is said to be in critical condition.
Two deaths are reported: a 75-year-old Saudi woman in Onaizah (first reported on November 13) and a 77-year-old Saudi woman in Buraidah. She must be the same person reported as being in critical condition; I find no mention of another such case in the past month of updates. Usually such same-day fatal cases are described as "expired."
No recoveries are reported for the 18th, and no new cases, deaths, or recoveries are reported for the 19th either.