Cybersecurity Governance Deficiencies in External Audit: A Structured Review and Control-to-Assertion Framework

Digital financial reporting depends on identity services, enterprise systems, cloud platforms, automated controls and system-generated evidence. Cybersecurity weaknesses therefore enter external audit when a governance condition or control deficiency affects a material reporting process, an assertion, a disclosure, an estimate or the reliability of audit evidence. This article develops a non-deterministic control-to-assertion framework through a structured integrative review. The search, completed on 16 July 2026, covered English-language journal work published from 2000 to 15 July 2026 through Google Scholar and publisher search services. The final analytic set contains 32 peer-reviewed journal articles, four institutional sources and two public company filings used for worked application. The revision separates organisation-level cybersecurity governance deficiencies from process-level cyber control deficiencies. It also locates the model against COSO, COBIT 2019, NIST CSF 2.0, IT general control methods and relevant International Standards on Auditing. Existing sources provide taxonomies for governance, internal control, security outcomes and audit procedures. The new framework supplies the missing translation route between those taxonomies: governance condition, control state, financial reporting dependency, assertion-level misstatement risk, audit-evidence reliability, audit response and reassessment. Compensating, detective and corrective controls might interrupt or reduce the route, so no governance deficiency automatically produces a control failure or a material misstatement. Two worked documentary applications, The Clorox Company and MGM Resorts International, show how public incident facts enter account, assertion, evidence and procedure analysis. The framework does not estimate incident probability, expected loss or a cyber risk score. It provides a file-ready reasoning structure for entity-specific risk assessment under the auditing standards. Its main contribution lies in the separate treatment of misstatement risk and evidence reliability, followed by a traceable link to accounts, assertions, evidence sources, specialist input and audit procedures.