Its survey of 347 company risk managers looked at the biggest concerns for the next 18 months, after the pandemic shut down much of the world economy.
They identified the most likely fallout as an extended downturn, a jump in company failures allied with industry consolidation, and high youth unemployment.
The findings of the survey, conducted in the first half of April, were consistent with many economists' forecasts that a rapid "V-shaped" recovery is unlikely.
A different poll on Monday said that a majority of some of Europe's most powerful chief executives believe that the recovery will take up to two years.
The debt accrued in the rescue packages could depress government and corporate finances and retard growth for years, and also stymie efforts to combat climate change, the World Economic Forum survey said.
Some 500 million people risk falling into poverty, undoing gains made over recent decades, and a "lost generation" of children and young adults could be at hand.
The crisis has "revealed the inadequacies of the past", said Saadia Zahidi, managing director of the WEF.
"Not only do we have bigger government, we also have the possibility of bolder government," she told an online briefing, noting that governments were already attaching conditions to corporate bailouts.
Those include demands for airlines, for example, to use cleaner fuels, she said, flagging a chance for governments to build "a more people-centric and planet-centric economy".
The crisis could prove to be a "structural break" with the old economy, agreed Peter Giger, group chief risk officer at Zurich Insurance, which contributed to the report.
"The challenge is not to build back but to rebuild with a forward-looking perspective," he said at the briefing.
"The planet continues heating up. And that's true of a whole range of risk exposures."
The WEF organises an annual meeting of political and corporate leaders in Davos, Switzerland.
Ahead of this year's conclave in January, when the COVID-19 outbreak was still largely confined to China, the forum's annual risk report showed climate change as the biggest concern for companies over the next 10 years.
But it also flagged up anxiety that health systems around the world were ill-prepared for another pandemic.
A second wave of COVID-19 was another concern identified in Tuesday's report, along with the dangers of cyberattacks and data fraud as much corporate activity shifts online.
Ngaire Woods, dean of the Blavatnik School of Government at the University of Oxford, also highlighted the risk of "economic xenophobia" and outright conflict as countries trade blame for the outbreak.
"No government can afford that at the moment," she said at the WEF briefing.
US President Donald Trump is threatening to pull the United States out of the World Health Organization, accusing it of botching the response and of being a "puppet of China".
Woods added that economically, governments have become "the investors of last resort" for many companies.
That gives them "the right to set new terms, a new deal, for corporate responsibility".