A massive Microsoft 365 outage disrupted services for hundreds of thousands of users worldwide, leaving many unable to access emails, Teams chats, or meetings. The incident began around 6pm UTC on Thursday and lasted over nine hours, affecting businesses, government agencies, and even Microsoft employees. The outage was caused by a configuration update that overloaded servers, making them unresponsive. Microsoft attempted fixes, but some servers became unresponsive again as traffic returned, prolonging the downtime.
By 2am Friday UTC, Microsoft had narrowed down most issues to Microsoft Exchange, the email service behind Outlook. Teams meetings and chats had resumed, but the outage highlighted the world's growing reliance on online services. RMIT associate professor Mark Gregory emphasized the need for thorough testing of updates before deployment and suggested companies have backup options like Google’s Gmail or LibreOffice to mitigate such outages.
Speculation about a cyber-attack arose, especially following recent incidents like the OpenAI agent attack on Medicare and other cyber-attacks in Europe. However, Microsoft dismissed the idea, stating there was no indication of a cyber-attack. The outage underscored the vulnerabilities of modern cloud-based services, where brief disruptions can have widespread impacts.