Yahoo has received multiple bids at or above $5 billion for core business

Yahoo has received multiple bids at or above $5 billion for its core business, CNBC has learned.

To be sure, it's a mystery what exactly is up for auction — each bid could contain slightly different assets, including parts of intellectual property and real estate — and bids will shake up again as the next round of the auction commences. But there are bids of $5 billion or more for the core business, excluding any real estate or patent portfolio, according to people familiar with the situation.

Verizon Communications bid more than $3.5 billion, making it among lower bids received by the technology company.

Yahoo's board of directors is planning on meeting Friday to review the second round of bids for its core business, as it struggles to separate its stake in Asian assets like Yahoo Japan and Alibaba amid pressure from activist investors.

The best bids will go on to a final round starting next week, CNBC has learned. Private-equity firms and strategic bidders will enter final round of bidding, which is expected to conclude by mid-July.

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— Reporting by CNBC's David Faber.