The Girls Aloud star contracted the tropical disease while on holiday in Tanzania with dancer pal Derek Hough, 25, last month.
Although Cheryl, 27, was transferred from intensive care to a private clinic on Friday, doctors have advised her to rest.
She will no longer perform at the V Festival in August and she will miss the boot camp stage of The X Factor later this month.
'Our priority is to ensure Cheryl is fit and well before she returns to work and to give our contestants a fair and proper opportunity to compete in the show,' a spokesman tells the BBC.
It has not been announced if a guest judge will replace Chezza.
- X Factor first pics
- More info on malaria.