We do extensive testing including stress testing and make use of tooling that can catch bugs early. We also partner with internal security teams to do fuzz test

We do extensive testing including stress testing and make use of tooling that can catch bugs early. We also partner with internal security teams to do fuzz testing and security reviews for all networking code. That said, none of the networking stacks deployed widely today are completely immune to security vulnerabilities. Responsible disclosure also plays an important role.