The shared office company's former boss stepped down in September after its botched initial public offering (IPO).
In a proposed class action filed last week in San Francisco Superior Court, former WeWork employee Natalie Sojka accused the company's board of directors of breaching its fiduciary duties to minority shareholders like herself.
Sojka faulted the board for letting Japan's Softbank rescue WeWork by boosting its stake to a potential 80 percent from 29 percent at a "firesale" price, and granting Neumann a $1.7bn exit package.
Softbank and its chairman, Masayoshi Son, are among the 10 named defendants in the complaint, which also accuses them and Neumann of self-dealing.
"Wework believes this lawsuit is meritless," a spokesperson said.
WeWork's parent company, the We Company, shelved its IPO on September 30 after investors grew wary of its losses, its business model and its corporate governance.
Estimates of WeWork's valuation have sunk to as little as $5.9bn, based on the value of Softbank's proposed $9.5bn rescue, from $47bn in August.
The Wall Street Journal reported yesterday the We Company had been wrangling with the US Securities and Exchange Commission in the run up to its planned listing. On September 11 the regulator reportedly sent the shared-workspace company a list of 13 still unresolved concerns covering issues such as how it framed its heavy losses.
Last week WeWork revealed plans to divest all non-core businesses and cut jobs, while Neumann's former chief of staff sued him a few days earlier for pregnancy discrimination.
Former WeWwork employee Sojka said the defendants caused a big drop in the stock's value, and threatened "irreparable harm" from the Softbank rescue and other transactions.