Interim CISO 60-Day Integration Plan After an Acquisition

Use the first 60 days to restore control, clear the fog, and keep the deal moving.

Hero image: Two leadership teams reviewing access, vendor, and reporting gaps in the same room.

After an acquisition, you inherit two companies, two ways of working, and one leadership team that needs answers fast. The real problem is not the handoff itself. It is the delay, the duplicate tools, the unknown access, and the half-finished decisions that start acting like permanent controls.

If you are the interim CISO, your job is to restore control. If you are the CEO, CFO, board member, or deal sponsor, your job is to know what good looks like before the noise starts to sound normal. This is not a tool rollout or a giant policy rewrite. It is a decision plan that protects the deal and keeps the business moving.

TL;DR

• Start with business risk, not the backlog. Focus on revenue, operations, legal exposure, and trust.

• Treat the first 60 days as control work, not transformation work. You are stabilizing, not perfecting.

• Name the knowns, unknowns, and assumptions early. False comfort is expensive.

• Make access, evidence, and reporting boring and reliable. That is what keeps surprises from spreading.

• Lock down decision rights before you debate tools or standards.

• End with clear owners, dates, and next steps so leadership can approve, defer, or send work back.

If you cannot say who owns the risk, you do not have an integration plan yet. You have a delay.

Start with the risks that can hurt the deal, not the security backlog

Your first questions should be simple. What could stop revenue? What could slow customers? What could expose the company to legal trouble? What could shake trust with the board, regulators, or key clients?

Use three lenses from day one: risk clarity, governance, and execution. Risk clarity tells you what matters. Governance tells you who decides. Execution tells you what gets done and tested.

The highest-value systems are usually easy to name once you stop talking in generalities. You are looking for the places where failure hurts the business, not the places with the longest vulnerability list.

Identify the systems, vendors, and data paths that matter most

Map the crown jewels first. That usually means identity, finance systems, customer data, cloud access, endpoints, and the vendors that sit in the middle of them.

Ask plain questions:

• If this system fails, does revenue stop?

• If this vendor slips, does the close delay?

• If this data leaks, does trust drop?

• If this access path is weak, can someone move too far too fast?

If you are also dealing with a shaky response model, pull in board incident response oversight early. After a deal closes, response gaps are where small mistakes become loud ones.

Separate confirmed facts from unknowns and assumptions

Build a short list with three columns in your head, or on paper, or in the board packet: known, unknown, assumed. That sounds basic because it is. Basic is good when the stakes are high.

If the evidence is thin, say so. Then explain how you will validate it anyway through sampling, access checks, segmentation, compensating controls, or monitoring. Weak evidence with strong language is how teams fool themselves.

Use the first 30 days to get control of access, evidence, and reporting

The first month is about shrinking the blast radius. You do that by cleaning up access, collecting proof, and giving leaders a reporting rhythm they can trust.

Do not wait for a perfect target state. Perfect is how you end up with temporary exceptions that never leave.

Lock down access and remove inherited surprises

Acquired environments always carry hidden permissions. Some are accidental. Some are old. Some were added because nobody wanted to interrupt a deal.

Review:

• privileged access

• shared accounts

• orphaned users

• third-party access

• temporary exceptions

Your moves are simple. Revoke what should not exist. Reduce what is broader than it needs to be. Segment what cannot be cleaned up right away. Verify what management says is true.

Turn messy inputs into board-ready reporting

Busy reporting is not the same as real exposure. A long list of issues can still hide the few that matter most. You need a small set of risks, a named owner for each one, and a clear escalation path.

If you want a model for useful reporting, start with board cybersecurity reporting and the perfect board cyber update. The point is not more slides. The point is a clean answer to three questions: what changed, what it means, and what decision is needed.

Use days 31 to 60 to align the two companies around one risk model

By the second month, you should stop acting like two separate security shops. The goal is not just to merge tools. It is to merge decisions.

That means one view of priority risks, one way to approve exceptions, one response model, and one list of remediation work that leadership can defend.

Set decision rights before you debate tools

If nobody knows who can approve risk, fund fixes, or accept exceptions, the integration will stall. Decision rights are a control. Treat them that way.

Name one accountable business owner for each major issue. Not a security contact. A real owner. Someone who can take the call, fund the fix, or accept the risk in public.

A useful reference point is defining decision rights. Without that clarity, the loudest voice wins, and the board gets a lot of motion with very little movement.

Choose the few fixes that cut the most risk fast

Not every gap deserves immediate work. You are looking for the few fixes that change the risk profile fast.

Common first moves include identity cleanup, vendor contract changes, logging improvements, backup validation, and network segmentation. When you present options, keep them plain:

• accept risk

• fund mitigation

• require a contract change

• plan exit

Recommend one path. Give a rough cost range. Give a timing range. Give the business reason. That is better than a vague promise to "improve maturity."

Close the 60-day plan with decisions, owners, and a clear next step

By day 60, leadership should be looking at a short list of decisions, not a pile of status updates. The final output should tell them what they can approve, defer, or send back.

Every open item needs a named owner, a date, and a follow-up rhythm. If the issue is still unresolved, say what proof is missing and when you will have it. The goal is not more meetings. The goal is visible closure and better accountability.

If the gap is wider than the team can close alone, use Get Board-Ready on AI and Cyber Risk for a direct advisory conversation that helps sort the next move.

Frequently asked questions

What should an interim CISO own in the first 60 days?

You should own risk triage, access cleanup, reporting discipline, and the decision model. You are there to restore control.

What should business leaders own?

They should own the actual business calls, funding decisions, and risk acceptance. Security can recommend. Leadership decides.

How much should change in 60 days?

Enough to reduce real exposure. Not enough to churn the environment for sport.

What does good reporting look like?

Short, plain-English, and decision-shaped. It should show the top risks, the owner, the next step, and the date you will revisit it.

Read related pieces

• See Where Your Board Actually Stands

• Cybersecurity as Business Risk Management

Conclusion

A strong interim CISO 60-day integration plan after acquisition does one thing well. It gives you control before confusion hardens into habit.

When the first 60 days go right, you know what matters, who owns it, what still needs proof, and what happens next. That is the job. Not staying busy. Creating a defensible path forward after the acquisition.