In a statement to the City, the FTSE 250 firm said the approach was "non-binding" and may or may not lead to a formal offer.
"The Board is currently considering its response to the approach. There is no certainty ... as to the price at which any offer might be made," it said.
The admission was enough to send shares in Micro Focus up 10% yesterday, valuing the business at close to £700m.
According to reports, the potential buyer is thought to be a private equity consortium.
The firm has also taken the decision to suspend an ongoing buyback programme until further notice in light of this latest development.