New NatJack Attacks Hijack TCP Sessions and Spoof DNS by Manipulating NAT Tables

Summary

Security researcher Malcolm Stagg has disclosed a new attack class called NatJack that manipulates network address translation (NAT) connection state to hijack active TCP sessions, spoof DNS responses, expose mapped ports, and exhaust NAT tables. Presented at Black Hat USA 2026, the research found affected behavior across independently developed implementations, including Windows and