Strauss Borrelli PLLC, a leading data breach law firm, is investigating F5, Inc. (“F5”) regarding its recent security incident. According to F5’s regulatory and customer communications, a sophisticated threat actor maintained persistent access to portions of F5’s environment and exfiltrated certain files.1
ABOUT F5, INC.:
F5 provides multicloud application security and delivery solutions, including BIG IP and related offerings, and states it is trusted by a significant share of large enterprises. Headquartered in Seattle, Washington, F5 employs over 5,000 individuals.2
WHAT HAPPENED?
In an official Securities and Exchange Commission (SEC) filing, filed October 15, 2025, F5 reported that on August 9, 2025 it learned a “highly sophisticated nation-state” actor had gained unauthorized access to certain company systems. In response, F5 began an investigation to determine the nature and scope of the incident.
During the investigation, F5 determined the actor had long-term, persistent access to the BIG-IP product development environment and engineering knowledge management platform, and exfiltrated files containing portions of BIG-IP source code and information about undisclosed vulnerabilities F5 was working on.4
F5 determined that some exfiltrated files contained configuration or implementation information for a small percentage of customers; F5 states it will communicate directly with affected customers as appropriate.
If you believe you may have been affected by the F5, Inc.:
We would like to speak with you about your rights and potential legal remedies in response to this security incident. Please fill out the form, below, or contact us at 872.263.1100 or sam@straussborrelli.com.
