WASHINGTON — Delta Air Lines initiated a lawsuit against the cybersecurity company CrowdStrike in a Georgia state court on Friday after a significant outage in July led to numerous flight cancellations, impacting travel for over 1.3 million customers and resulting in losses exceeding $500 million for the airline.

In its lawsuit filed in Fulton County Superior Court, Delta labeled the problematic software update from CrowdStrike as “catastrophic” and accused the firm of pushing out “untested and erroneous updates,” which caused more than 8.5 million Microsoft Windows computers globally to crash.

The incident on July 19 resulted in worldwide flight cancellations and had repercussions across various sectors, including banking, healthcare, media, and hospitality.

“Delta’s allegations are based on false information, reveal a misunderstanding of modern cybersecurity, and represent a desperate attempt to divert attention from its inadequate recovery efforts due to its outdated IT systems,” a CrowdStrike spokesperson stated late Friday.

Delta, which has been a CrowdStrike customer since 2022, indicated that the outage forced the cancellation of 7,000 flights, affecting 1.3 million passengers over a span of five days.

Delta is seeking over $500 million in direct losses from CrowdStrike, along with additional claims for lost profits, legal expenses, and “reputational damage and future income loss.”

The incident has prompted an investigation by the U.S. Department of Transportation.

“Had CrowdStrike properly tested the erroneous update on just one computer before its release, the issue would have been identified,” Delta’s lawsuit states. “Since the faulty update could not be uninstalled remotely, CrowdStrike severely disrupted Delta’s operations and caused significant delays for its customers.”

Delta emphasized that as part of its IT strategy, it has invested billions of dollars “in acquiring and developing leading technology solutions within the airline sector.” CrowdStrike has raised questions regarding why Delta experienced such severe issues compared to other airlines and has stated its liability is limited, a claim Delta disputes.

Last month, a senior CrowdStrike executive expressed regret before Congress for the flawed software update.

Adam Meyers, a senior vice president at CrowdStrike, admitted that the company released a configuration update for its Falcon Sensor security software that led to system failures worldwide. “We sincerely apologize for this incident and are committed to ensuring it doesn’t happen again,” Meyers said.

This article was updated to fix a typo.