Hackers Are Selling a Critical Zoom Zero-Day Exploit for $500,000 People who trade in zero-day exploits say there are two Zoom zero-days, one for Windows and one for MacOS, on the market. Hackers are selling two critical vulnerabilities for the video conferencing software Zoom that would allow someone to hack users and spy on their calls, Motherboard has learned. The two flaws are so-called zero-d