M&A identity security risks and the governance gap teams miss

TL;DR: Mergers and acquisitions can double identity risk during integration, while mismatched IAM stacks, provisional access, SoD conflicts, compliance gaps, and inherited breaches create a larger attack surface, according to Unosecur and cited research. In practice, merger governance fails when teams treat identity consolidation as a back-office task instead of a security prerequisite.

NHIMG editorial — based on content published by Unosecur: Six identity security risks in M&A and how to mitigate them

By the numbers:

• A research report published in 2023 found that the risk of a cybersecurity incident is twice the average during a merger or acquisition.
• 65% of executives regretted an acquisition after discovering post-merger security issues.

Questions worth separating out

Q: What breaks when identity governance is not in place during an acquisition?

A: Without identity governance, merger teams lose track of who owns access, which accounts are temporary, and where privileged rights overlap.

Q: Why do mergers and acquisitions increase identity security risk so quickly?

A: M&A increases risk because the combined estate usually contains more identities, more privileged accounts, and two different governance models.

Q: How do security teams know if merger access controls are working?

A: They should be able to show that every temporary account has an owner, an expiry date, and a review record, and that privileged access is being monitored for unusual use.

Practitioner guidance

• Baseline both identity estates before close Inventory directories, privileged accounts, service accounts, contractor access, and third-party connections across both organisations before migration decisions are made.
• Time-box every provisional access grant Require explicit expiry dates, approval ownership, and recertification for all merger-related access, including temporary admin rights and external support accounts.
• Run SoD conflict analysis on the merged role model Test the combined access model for toxic combinations that did not exist inside either company alone, then block conflicting role assignments before production cutover.

What's in the full article

Unosecur's full blog covers the operational detail this post intentionally leaves for the source:

• A practical breakdown of how to assess identity security posture across two separate IAM estates before integration.
• Examples of the six merger-specific identity risks, including role conflicts, compliance drift, and inherited compromise.
• Consulting-led mitigation patterns for PAM, ITDR, and IAM operations in live acquisition environments.
• The article's own framing of post-merger identity risk from a client advisory perspective.

👉 Read Unosecur's analysis of six identity security risks in M&A →

M&A identity security risks and the governance gap teams miss?

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