Some Logan airport flights, Mass. General Brigham hospitals affected by major Microsoft outage

A major internet outage affecting Microsoft is disrupting flights, banks, media outlets and companies across the world, with problems continuing hours after the technology company said it was gradually fixing an issue affecting access to Microsoft 365 apps and services.

Airlines and airports in the United States, Europe, Australia, India and elsewhere were reporting problems, with some flights grounded. Retail outlets, banks, railway companies and hospitals in several parts of the world were also affected in what appeared to be an unprecedented internet disruption.

In Boston, a spokesperson for MassPort advised travelers to check with their airlines before coming to Logan Airport. As of 10:50 a.m., Logan Airport was showing 194 delays and 59 cancellations via the website FlightAware.com.

At Logan Friday morning, Elly from Washington State told GBH News that she was on her way home after visiting a childhood friend. She said got a text message during her ride to the airport, saying her flight was canceled. She was waiting in a long line at Delta Airlines’ terminal to find out what her options were.

“I have a connection in Seattle,” she said, “but my new flight is supposed to — if it’s true that there’s a new flight, I don’t know — it’s supposed to land at the same time my connection takes off. So I’m going to have to talk to an agent to try and sort that out.”

Elly said she might end up renting a car and driving three and a half hours over the Cascade Mountains to her home in Eastern Washington.

The outage also affected health care in the Boston area. Mass General Brigham canceled all non-urgent visits at their hospitals, health care centers, and outpatient clinics for Friday.

“Mass General Brigham remains open to provide care to patients with urgent health concerns in our clinics and emergency departments, and we continue to care for all patients currently receiving care in our hospitals,” hospital officials said in a statement.

Cybersecurity firm CrowdStrike said that the issue believed to be behind the outage was not a security incident or cyberattack — and that a fix was on the way. The company said the problem occurred when it deployed a faulty update to computers running Microsoft Windows.

But hours after the problem was first detected, the disarray continued — and escalated.

Long lines formed at airports in the U.S., Europe and Asia as airlines lost access to check-in and booking services at a time when many travelers are heading away on summer vacations. News outlets in Australia — where telecommunications were severely affected — were pushed off air for hours. Hospitals and doctor’s offices had problems with their appointment systems, while banks in South Africa and New Zealand reported outages to their payment system or websites and apps.

Some athletes and spectators descending on Paris ahead of the Olympics were delayed, but Games organizers said disruptions were limited and didn’t affect ticketing or the torch relay.

DownDectector, which tracks user-reported disruptions to internet services, recorded that airlines, payment platforms and online shopping websites across the world were affected — although the disruption appeared piecemeal and was apparently related to whether the companies used Microsoft cloud-based services.

Cyber expert James Bore said real harm would be caused by the outage because systems we’ve come to rely on at critical times are not going to be available. Hospitals, for example, will struggle to sort out appointments and those who need care may not get it.

“There are going to be deaths because of this. It’s inevitable,’’ Bore said. “We’ve got so many systems tied up with this.”

Microsoft 365 posted on social media platform X that the company was “working on rerouting the impacted traffic to alternate systems to alleviate impact” and that they were “observing a positive trend in service availability.”

The company did not respond to a request for comment.

CrowdStrike said in an emailed statement that the company “is actively working with customers impacted by a defect found in a single content update for Windows hosts.”

It said: “This is not a security incident or cyberattack. The issue has been identified, isolated and a fix has been deployed.”

The Austin, Texas-based company’s Nasdaq-traded shares were down nearly 15% in premarket trading early Friday.

A recording playing on its customer service line said, “CrowdStrike is aware of the reports of crashes on Microsoft ports related to the Falcon sensor,” referring to one of its products used to block online attacks.

Meanwhile, governments, officials and companies across the world scrambled to respond.

GBH News contributed to this story with details on how the outage was affecting Boston travel and hospitals.