Kiteworks lifts advisory after precautionary warning for customers to shut down systems

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The firm had received information from law enforcement of a possible attack.

Published Sept. 28, 2026

Two days after advising customers to take their systems offline, Kiteworks on Sunday canceled its precautionary guidance. 

After receiving information from federal authorities of a potential threat, the company on Friday issued an advisory for customers to temporarily take their systems offline.  

"Kiteworks received credible threat intelligence from federal intelligence authorities indicating that a threat actor may attempt to target some Kiteworks systems for customers,” Kiteworks CISO Frank Balonis told Cybersecurity Dive Friday in a statement. “Out of an abundance of caution, we notified customers directly and recommended a precautionary shutdown window while we and our law enforcement partners work through the matter.”

Researchers at Sophos said the warning was related to possible exploitation of a zero-day vulnerability. 

California-based Kiteworks, previously known as Accellion, offers a platform to enable secure communication with customers, vendors and other partners.

Kiteworks advised customers with self-managed systems either on-premises or through Azure or AWS to shut down their systems for a nine-hour period, while the threat was investigated. 

On Friday, the company said it was not aware of any confirmed compromise, adding that the advisory was a preventative action rather than a response to any confirmed breach. 

The company said all known vulnerabilities were addressed in the current security update 9.5.1. 

Kiteworks lifted the advisory on Sunday, but did not provide any specifics about what was found during the investigation.