Unmanaged certificates create hidden expiration risk, inconsistent policy enforcement, and delayed revocation when keys are exposed or staff leave. Private keys stored on servers or file systems can be stolen, copied, or misused, enabling impersonation and service disruption. In regulated sectors, those failures can also trigger audit gaps, breach notification obligations, and sanctions.
Why This Matters for Security Teams
Unmanaged certificates and private keys are not just housekeeping issues. They are trust anchors for TLS, signing, service-to-service authentication, and privileged automation. When ownership is unclear, expiry dates are missed, and revocation is slow, outages and impersonation follow. That creates operational drag and also weakens evidence for audit, change control, and incident response under frameworks such as the NIST Cybersecurity Framework 2.0 and the Ultimate Guide to NHIs — Regulatory and Audit Perspectives.
NHIMG research shows why this risk is hard to ignore: 53% of organisations have experienced a security incident directly related to machine identity management failures, and only 38% have automated certificate lifecycle management in place, according to The Critical Gaps in Machine Identity Management report from SailPoint. The issue is not limited to expiration. Private keys stored on servers, file shares, or CI/CD systems can be copied silently, then reused to impersonate trusted workloads long after the original owner has moved on. In practice, many security teams discover the problem only after a failed renewal, an exposed key, or an audit finding has already forced emergency response.
How It Works in Practice
Certificate and key risk usually emerges from weak lifecycle control, not from cryptography itself. A certificate may be issued correctly, but if the inventory is incomplete, the owner is unknown, or renewal depends on manual reminders, the organisation inherits hidden operational debt. Private keys are even more sensitive: once they leave secure generation and storage paths, the control problem becomes one of containment, access governance, and rapid revocation.
Current best practice is to treat certificates and keys as managed non-human identities, with clear ownership, short validity periods where possible, and automated renewal and revocation workflows. That means tying issuance to approved workloads, integrating with NIST SP 800-53 Rev 5 Security and Privacy Controls for access, audit, and configuration management, and maintaining an inventory that can answer three questions at any time: what exists, who owns it, and when it expires. NHIMG’s NHI Lifecycle Management Guide and Top 10 NHI Issues both stress that lifecycle visibility is the practical control plane.
- Issue certificates through approved workflows, not ad hoc requests.
- Store private keys in hardened systems, hardware-backed modules, or managed secret services where feasible.
- Automate renewal, rotation, and revocation based on policy and ownership.
- Log issuance, use, and disposal events so auditors can trace exceptions.
- Align key access with least privilege and separation of duties.
These controls tend to break down when certificates are embedded in legacy appliances, scripts, or unmanaged cloud resources because renewal and revocation cannot be enforced consistently across those environments.
Common Variations and Edge Cases
Tighter certificate and key control often increases operational overhead, requiring organisations to balance security assurance against deployment friction and legacy compatibility. That tradeoff is real, especially where uptime-sensitive systems, external partner integrations, or embedded devices cannot easily support frequent rotation.
There is no universal standard for every renewal interval or storage pattern yet, so guidance varies by risk profile and system criticality. For high-value services, short-lived certificates and automated rotation are usually preferred. For slower-moving legacy platforms, compensating controls may be needed, such as stricter network segmentation, enhanced monitoring, and explicit exception approval. The same applies to private keys used for code signing or document signing: the blast radius is often larger than for ordinary TLS endpoints, so protection and dual control should be stronger.
Compliance teams should also distinguish between expired certificates, exposed keys, and undocumented keys. Each can create a different audit finding, and each may trigger different obligations under internal policy or external regimes. NHIMG’s Ultimate Guide to NHIs — Key Challenges and Risks and Ultimate Guide to NHIs — Why NHI Security Matters Now are useful references when teams need to separate routine lifecycle risk from a true governance failure.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 address the attack and risk surface, while NIST CSF 2.0, NIST SP 800-63, NIST Zero Trust (SP 800-207) and NIST AI RMF set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-03 | Expired or unmanaged secrets are a core NHI lifecycle failure. |
| NIST CSF 2.0 | PR.AC-4 | Least-privilege access is required for private key and certificate handling. |
| NIST SP 800-63 | Identity assurance concepts help validate issued credentials and their binding to workloads. | |
| NIST Zero Trust (SP 800-207) | Zero trust supports continuous verification for machine authentication. | |
| NIST AI RMF | AI risk governance is relevant when automated systems manage identity lifecycle decisions. |
Inventory certificates and keys, then automate renewal, rotation, and revocation before expiry or exposure.
Related resources from NHI Mgmt Group
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Reviewed and updated by the NHIMG editorial team on August 24, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
