Cybersecurity firm F5's stock sinks 12% after disclosing nation-state hack
1. F5 shares fell 12% after disclosing a system breach. 2. A sophisticated nation-state actor accessed F5 systems long-term. 3. The breach involved the BIG-IP product development environment. 4. CISA urged immediate action from agencies using F5 products. 5. Threat attributed to state-backed hackers from China.