Mergers and acquisitions create a long list of technology decisions. Systems need to be connected, employees need access to new resources, applications may need to be consolidated, and data has to move between environments. At the same time, two organizations with different IT policies, security practices, networks, vendors, and technology stacks suddenly become part of the same business environment.
That transition creates opportunity, but it can also create cybersecurity exposure.
Avoiding the security gaps that emerge during mergers requires more than completing a technology migration. It requires understanding what each organization is bringing into the combined environment, identifying weaknesses before they become larger problems, and establishing consistent security controls as systems are integrated.
For private equity firms and the portfolio companies they support, this can be especially important during acquisition and post-close integration. Technology decisions made early in the process can affect security, operational continuity, compliance, and the ability to standardize IT across the organization.
Why Mergers Create IT and Cybersecurity Gaps
Every company has its own way of managing technology. One organization may use Microsoft 365 while another relies on a different productivity platform. One may have strong multi-factor authentication and documented access controls, while the other has accumulated years of legacy accounts and inconsistent permissions.
Both organizations may function adequately on their own.
The problem appears when their environments need to interact.
Connecting two networks, migrating users, combining cloud applications, sharing files, or creating new accounts can introduce security gaps that did not previously exist. A connection between two environments creates another pathway that needs to be secured and monitored.
NIST guidance on IT system interconnections emphasizes planning, establishing, maintaining, and eventually terminating connections with security considerations throughout the lifecycle. The same principle applies during an acquisition: integration should be treated as an ongoing security process rather than a single technical cutover. NIST’s guidance on securing interconnected IT systems provides a useful framework for thinking about these connections.
Common Security Gaps During Mergers and Acquisitions
Security gaps do not always come from obvious vulnerabilities. Sometimes they result from inconsistent processes, incomplete documentation, or assumptions about how the other organization manages IT.
Different Security Standards
Two companies may have completely different approaches to cybersecurity.
One may require multi-factor authentication for every employee, while the other uses it only for administrators. One may routinely patch endpoints, while the other has older devices that have not been consistently maintained.
When those environments are combined, the weaker practices can become part of the larger organization’s risk profile.
This is why private equity cybersecurity should begin with understanding the current state of each company rather than assuming that every acquired business follows the same standards.
Unknown or Excessive User Access
Employee accounts are another common source of risk during an integration.
An acquired company may have employees, contractors, former employees, vendors, and administrators with access to systems that have not been reviewed recently. Once systems begin connecting, those existing permissions may provide access to additional resources.
Access reviews should identify:
- Active employee accounts.
- Former employee accounts.
- Administrative accounts.
- Shared accounts.
- Vendor and contractor access.
- Remote access accounts.
- Inactive accounts.
- Users with excessive permissions.
Access should then be aligned with each person’s actual responsibilities.
Unmanaged Devices
Acquisitions can also introduce computers, laptops, mobile devices, servers, network equipment, and other technology that the acquiring organization has not previously managed.
Without a complete asset inventory, it can be difficult to determine which devices are protected, which require updates, and which may no longer be supported.
A device that was acceptable within the acquired company’s previous environment may not meet the security requirements of the combined organization.
IT Due Diligence Should Begin Before Integration
One of the most effective ways to reduce integration risk is to begin evaluating technology before systems are connected.
IT due diligence can help identify cybersecurity concerns, outdated technology, licensing issues, unsupported systems, infrastructure limitations, vendor dependencies, and other potential problems.
NIST’s 2026 Cybersecurity Supply Chain Risk Management Due Diligence Assessment Quick-Start Guide emphasizes due diligence as a way to research and verify relevant risks before acquisition decisions are executed. While its specific scope addresses ICT suppliers, its broader risk-based approach reinforces the value of understanding technology and cybersecurity conditions before relying on or integrating them. NIST’s 2026 due diligence assessment guidance provides additional context.
For private equity firms, technology due diligence can provide a clearer picture of what will be required after a transaction closes.
Questions should include:
- What systems does the company depend on?
- Which applications are business-critical?
- What cybersecurity tools are currently deployed?
- How are users authenticated?
- Where is company data stored?
- Are backups available and tested?
- Which systems are approaching end of life?
- What vendors have administrative or remote access?
- Are there unresolved cybersecurity incidents?
- What technology contracts or licenses need to be transferred or replaced?
- How is remote access currently managed?
- What regulatory or contractual technology requirements apply?
The answers help establish a baseline before integration begins.
Creating a Technology Baseline After Acquisition
Once the acquisition closes, the next step is creating a clear picture of the combined environment.
This does not necessarily mean standardizing everything immediately. Attempting to change every system at once can create unnecessary disruption.
Instead, the organization can establish a baseline for security and technology management.
Inventory Hardware and Software
An accurate inventory should identify the organization’s important technology assets.
This can include servers, workstations, laptops, networking equipment, cloud applications, business applications, security tools, and other systems that support operations.
Without this visibility, IT teams can easily overlook an outdated system or an application that still contains sensitive information.
Map Critical Systems and Dependencies
Not every system has the same importance.
Leadership should understand which applications support revenue-generating activities, financial operations, communications, customer service, and other critical functions.
Mapping these dependencies can help IT teams determine what needs to be integrated first, what can remain separate temporarily, and what should receive additional protection during the transition.
Document the Existing Environment
Documentation can be particularly valuable during a merger because knowledge that previously existed inside one organization’s IT department may not automatically transfer to the combined company.
Network diagrams, application inventories, vendor information, administrative accounts, licensing records, backup procedures, and other documentation can help create continuity during the transition.
Network Integration Can Introduce Significant Risk
One of the most important decisions during an acquisition is how and when networks should be connected.
It can be tempting to connect environments quickly so employees can access shared applications and resources. However, connecting networks before understanding their security posture can also allow problems in one environment to affect another.
Network support for private equity and portfolio companies should therefore include careful planning around network integration.
Before connecting environments, teams should understand:
- Network architecture.
- Firewall configurations.
- Remote access methods.
- Wireless networks.
- VPN connections.
- Administrative access.
- Critical servers and applications.
- Third-party connections.
- Network segmentation.
- Monitoring capabilities.
The goal is to establish connectivity without creating unnecessary pathways between systems.
Standardizing Identity and Access Management
Identity management becomes increasingly important when multiple organizations become one.
Employees need access to the systems required for their roles, but they should not automatically inherit every permission that existed in their previous environment.
A merger provides an opportunity to establish consistent standards around authentication and access.
Implement Strong Authentication
Multi-factor authentication should be considered for important systems, especially accounts with elevated privileges or access to sensitive information.
Standardizing authentication makes it easier for IT teams to manage accounts and apply consistent security policies across the organization.
Review Administrative Privileges
Administrative accounts can create significant risk if they are compromised.
During integration, organizations should identify who has administrative privileges and determine whether those privileges remain necessary.
Where practical, employees should use standard accounts for everyday work and separate administrative credentials for tasks requiring elevated access.
Remove Legacy Access
An acquisition is also an opportunity to eliminate unnecessary accounts.
Former employees, inactive contractors, outdated vendor accounts, and unused service accounts should be reviewed and disabled when appropriate.
This can reduce the number of credentials an attacker could potentially exploit.
Protecting Data During Migration
Data migration is another area where security gaps can appear.
Companies may need to move files, databases, email, customer information, financial records, or other sensitive information between systems. During that process, data may temporarily exist in locations that were not part of the original security architecture.
Migration plans should account for where information is stored, who can access it, how it is transferred, and how temporary copies are handled.
Access should be limited to the people who need it for the migration, and sensitive data should remain protected throughout the process.
Do Not Overlook Email and Cloud Applications
Email is often one of the first systems employees need to access after an acquisition, which makes it an important part of integration planning.
Cloud applications can create similar challenges.
A company may rely on dozens of SaaS applications for accounting, project management, document storage, communication, sales, operations, and other functions. Some may be centrally managed, while others may have been purchased independently by individual departments.
These applications should be identified and evaluated as part of the broader technology integration process.
Questions should include:
- Who owns the application account?
- Who has administrator access?
- Where is company data stored?
- Does the application integrate with other systems?
- Are former employees still listed as users?
- Is multi-factor authentication available?
- Are there inactive or unnecessary integrations?
Unmanaged cloud applications can become easy-to-miss security gaps after an acquisition.
Vendor and Third-Party Access Needs Attention
Acquired businesses often have relationships with technology vendors, software providers, consultants, and other third parties.
Some of these vendors may have remote access to systems. Others may have administrator accounts or access to sensitive data.
Those relationships should be documented and reviewed.
The organization should know which vendors have access, what they can access, why they need it, and whether that access is still necessary after the merger.
Third-party access should not simply remain active because it was convenient before the acquisition.
Build Security Into the Integration Timeline
Security should not be treated as a final step after the technical integration is complete.
Instead, cybersecurity should be included throughout the integration timeline.
A practical sequence might include:
- Pre-close: Conduct IT and cybersecurity due diligence.
- Initial assessment: Inventory systems, users, devices, applications, vendors, and access.
- Risk identification: Prioritize significant vulnerabilities and security gaps.
- Planning: Define the desired technology and security standards.
- Integration: Connect systems using controlled, documented processes.
- Validation: Confirm that access, security controls, backups, and systems function as expected.
- Standardization: Bring the environment into alignment with established portfolio standards.
- Ongoing management: Continue monitoring and improving the environment after integration.
This approach helps prevent the common mistake of considering integration complete simply because employees can access the systems they need.
Why Managed IT Services Can Help During a Merger
Mergers can place significant demands on internal IT teams.
Employees still need day-to-day support while the IT department is simultaneously dealing with migrations, access changes, security assessments, network projects, application consolidation, and other integration work.
Managed IT services for private equity firms can provide additional technical resources during these transitions.
A managed IT provider can assist with areas such as:
- IT assessments.
- Network infrastructure.
- Cybersecurity monitoring.
- Endpoint management.
- Identity and access management.
- Cloud application support.
- Backup and business continuity.
- Technology migrations.
- Vendor coordination.
- Ongoing help desk support.
The specific responsibilities should be defined as part of the integration plan. The goal is to give leadership a clear understanding of who owns each technology task and prevent important responsibilities from falling between teams.
Post-Merger Validation Is Just as Important
An integration should not be considered finished when the last migration is complete.
Post-migration validation is an important opportunity to confirm that the combined environment is operating as intended.
Teams should verify user access, system functionality, data integrity, network connectivity, security controls, backups, and other critical components.
This is also a good time to identify issues that were not apparent during the initial integration.
Review User Access Again
Access can change quickly during a merger. Employees may change roles, teams may be consolidated, and new systems may become available.
A follow-up access review can identify permissions that are no longer appropriate.
Test Backups and Recovery
Backups should not simply exist. The organization should understand whether critical information can actually be recovered.
Testing recovery procedures can help identify problems before an emergency occurs.
Continue Monitoring
Security monitoring should continue after the integration project ends.
The combined environment will continue to change as employees are onboarded, systems are retired, new applications are added, and business operations evolve.
Avoiding the Security Gaps That Emerge During Mergers Requires Planning
Avoiding the security gaps that emerge during mergers starts with recognizing that technology integration is also a cybersecurity project.
Two companies can have completely different approaches to user access, networks, backups, cloud applications, endpoint security, vendors, and technology management. Connecting those environments without first understanding the differences can introduce unnecessary risk.
A structured approach to IT due diligence, network integration, identity management, data migration, vendor access, and post-migration validation can help organizations identify and address those gaps.
For private equity firms and portfolio companies, the process can also create an opportunity to establish consistent technology standards that make future integrations easier to manage.
Strengthen IT Support Before, During, and After an Acquisition
M&A technology integration does not have to become a disruption to the business. With the right planning, leadership can identify technology risks early, establish clear responsibilities, and build a roadmap for bringing the environment into alignment.
LG Networks works with private equity portfolio companies on technology assessments, integration planning, cybersecurity, migrations, network infrastructure, and ongoing IT management. Learn more about IT Support for Private Equity firms and how a structured IT strategy can support portfolio companies before, during, and after an acquisition.
The earlier technology and cybersecurity are included in the integration process, the easier it is to identify gaps before they become expensive problems.