11:53 AM EDT, 10/15/2025 (MT Newswires) -- F5 (FFIV) said Wednesday that a "highly sophisticated nation-state threat actor" breached certain of its systems, including the BIG-IP product development environment and engineering knowledge management platform.

The hacker stole certain files that contained parts of the BIG-IP source code and information about undisclosed vulnerabilities that the company was working on in BIG-IP, according to a filing with the US Securities and Exchange Commission.

The company said it has no evidence of access to or theft of data from its customer relationship management, financial, support case management, or iHealth systems, but some of the stolen files from its knowledge management platform had configuration or implementation information for "a small percentage of customers." F5 said it will reach out directly to affected customers.

The company said it believes that its actions to contain the hacker have been successful and that no new unauthorized access has been detected.

F5 said it learned about the incident on Aug. 9, and, more than a month later, the US Department of Justice determined that delayed public disclosure was warranted.

The company said the incident has not materially impacted its operations as of Wednesday.

F5 shares were down more than 3% in recent trading Wednesday.

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