Which of the following should an information security manager do FIRST when a vulnerability has...

According to the CISM Review Manual, the first step an information security manager should take when a vulnerability has been disclosed is to conduct a risk assessment to determine the likelihood and impact of the vulnerability being exploited, and the appropriate response strategy. Performing a patch update, a penetration test or an impact assessment are possible subsequent steps, but not the first one.

References = CISM Review Manual, 27th Edition, Chapter 3, Section 3.3.2, page 1331.