When dealing with a zero-day vulnerability, the first step is to ensure that the network's security team reviews the available information to understand the vulnerability's nature and potential impact. If a patch or fix is not immediately available, the team would need to assess the risk and look at mitigation strategies such as applying workarounds, increasing monitoring for suspicious activity, or disconnecting affected systems if necessary. Engaging with vendor announcements and advisories for temporary solutions or mitigation steps often precedes the release of a patch and is critical to short-term defense.