Which of the following is the best mitigation for a zero-day vulnerability found in mission-critical production servers that must be highly available?

While this option may enhance the security posture by isolating applications, it does not directly address the zero-day vulnerability in the existing production environment. Virtualization and containerization can also introduce complexity and potential downtime during migration, which is not ideal for highly available systems.

This approach would effectively contain the vulnerability and prevent exploitation, but it is impractical for mission-critical servers that require constant availability. Isolating these servers could lead to significant disruptions in service, which is not acceptable in high-availability scenarios.

Although patching is an ideal long-term solution for vulnerabilities, it may not be feasible for mission-critical systems requiring high availability. Rapid redeployment could lead to unplanned downtime and disruptions, making this option less suitable for such environments.