Cybersecurity Governance Briefing — October 19, 2025

Executive briefing: NIST's SP 800-171 Revision 3 became the definitive control baseline for protecting Controlled Unclassified Information (CUI) in May 2024. With the Department of Defense signalling that the Cybersecurity Maturity Model Certification (CMMC) rule will conclude in fiscal year 2025, contractors must update policies, assessment evidence, and supplier oversight to the new requirements now.

Key risk themes

Expanded asset scoping. Revision 3 formalises discovery of interconnected assets, cloud services, and contractor-operated tooling that touch CUI, closing loopholes from self-attested boundary diagrams.
Supply chain assurances. The proposed CMMC rule requires prime contractors to flow SP 800-171 controls to subcontractors and collect assessment results, elevating third-party oversight obligations.
Continuous monitoring expectations. DoD emphasises operational technologies such as log review, automated alerting, and vulnerability remediation metrics over once-a-year checklist assessments.

Control alignment

NIST SP 800-171 Rev 3, Control 3.12.4. Implement formal plan of action and milestone tracking tied to objective evidence, ensuring interim risk acceptance is approved by the Authorising Official.
CMMC Proposed Rule, § 170.19. Establish contractual language mandating timely subcontractor assessments, reciprocity terms, and access to system security plans.
NIST SP 800-171A Rev 3. Update assessment procedures to capture enhanced control families, including SC.L2-3.3.7 for network segmentation and CM.L2-3.4.9 for configuration change approvals.

Detection and response priorities

Centralise security event logs from enclave boundary controls, cloud enclaves, and manufacturing systems into tooling that supports 72-hour incident reporting to DoD per DFARS 252.204-7012.
Conduct purple-team exercises that validate containment and eradication procedures for credentials stored in source code repositories and build pipelines referenced in the CMMC proposed rule.

Enablement moves

Refresh executive risk dashboards to include estimated CMMC certification costs, subcontractor readiness status, and Rev 3 control completion percentages.
Coordinate procurement reviews so SaaS and managed service suppliers sign updated CUI handling addenda aligned to SP 800-171 Rev 3 and DFARS clause flow-downs.

Sources

Zeph Tech equips defense industrial base suppliers with Rev 3 control implementations, subcontractor assurance playbooks, and pre-assessment evidence packages to accelerate CMMC certification.