Access control failure is the breakdown of authentication or authorisation mechanisms allowing inappropriate system or data access, including compromised authentication, misconfigured permissions, or failure to revoke terminated employee access. Such failures may void cyber insurance coverage if deemed negligent, as courts have established that inadequate access controls constitute a breach of reasonable duty. Insurers require evidence of proper access management including role-based controls, regular access reviews, and prompt deprovisioning. Claims face heightened scrutiny when access failures are involved—insurers may deny coverage for systemic weaknesses they classify as maintenance failures rather than covered security incidents, particularly if organisations cannot demonstrate maintained access logs and enforcement of least privilege principles.

Access control failure is the breakdown of authentication or authorisation mechanisms allowing inappropriate system or data access, including compromised authentication, misconfigured permissions, or failure to revoke terminated employee access. Such failures may void cyber insurance coverage if deemed negligent, as courts have established that inadequate access controls constitute a breach of reasonable duty. Insurers require evidence of proper access management including role-based controls, regular access reviews, and prompt deprovisioning. Claims face heightened scrutiny when access failures are involved—insurers may deny coverage for systemic weaknesses they classify as maintenance failures rather than covered security incidents, particularly if organisations cannot demonstrate maintained access logs and enforcement of least privilege principles.