Which step should be performed immediately after identifying a critical vulnerability affecting internet-facing systems?

TheCCST Cybersecurity Study Guidestates that after confirming a vulnerability is relevant and critical, the next step is to apply available patches or mitigations as soon as possible to reduce the attack surface.

"When a critical vulnerability is identified, remediation steps such as applying patches or configuration changes should be implemented immediately to prevent exploitation."

(CCST Cybersecurity,Vulnerability Assessment and Risk Management, Vulnerability Remediation section, Cisco Networking Academy)