Atlassian data leak caused by stolen employee credentials. Atlassian has confirmed that a breach at a third-party vendor caused a recent leak of company data and that their network and customer information is secure. 2/17/23: Story and title updated to reflect new statements from both companies. Atlassian suffered a data leak after threat actors used stolen employee credentials to steal data from a third-party vendor. However, the company says its network and customer information are secure. Third-party company: Envoy.