Sabre GLBL Inc. employees are suing the travel industry software company, alleging it failed to protect their personally identifiable information from a cyberattack.

Sabre’s investigation into the leak concluded that more than 29,000 people, including four plaintiffs, were affected by the attack, according to court documents from the US District Court for the Northern District of Texas.

Providing sensitive information to Sabre is a condition of employment, an amended complaint filed Wednesday said. That data includes “names, dates of birth, Social Security numbers, addresses, contact information, financial account information, and other sensitive information,” the complaint said.

But Sabre said ...