Zoom Video Communications Inc. is calling in the equivalent of the cybersecurity cavalry after security lapses that have drawn attention from U.S. authorities and raised concerns with customers.

Zoom ZM, +6.19% , the online video-conferencing tool that has won mass popularity during the coronavirus pandemic, over the past two weeks has hired dozens of outside security consultants. They include former security and privacy experts from companies such as Facebook Inc. FB, -0.89% , Microsoft Corp. MSFT, -1.24% , and Google GOOGL, -2.41% , hoping to quickly address questions about security flaws, according to those involved in the effort.