PKI certificate failures expose the hidden cost of machine identity

At a glance

What this is: This analysis argues that PKI certificate failures are an identity governance problem, not just an infrastructure problem, because certificate scale, manual operations, and short lifecycles now outpace human oversight.

Why it matters: For IAM and NHI practitioners, PKI is part of machine identity control, so weak inventory, renewal, and governance practices can become direct security and availability risk.

By the numbers:

• 50% of organizations in the study say the new 47-day TLS validity rule is accelerating PKI modernization efforts

👉 Read CyberArk's analysis of the hidden cost of PKI and certificate failure

Context

PKI is the certificate-based trust layer that lets systems authenticate, encrypt, and exchange data without human intervention. In enterprise environments, the governance gap appears when certificate volume, renewal cadence, and ownership patterns become too large for manual control, which turns machine identity management into an availability and security issue rather than a back-office task.

This article is about why certificate failures surface as identity and access management failures when infrastructure teams lack inventory, automation, and policy enforcement. The starting point is typical of many large enterprises: the operational model has not kept pace with the scale of internal certificates, shorter public certificate lifecycles, and rising audit pressure.

Key questions

Q: How should teams govern certificates as part of machine identity management?

A: Treat certificates as machine identities with owners, lifecycle states, and policy controls. Build inventory, automate renewal, enforce revocation, and connect certificate governance to IAM, secrets, and incident response so trust relationships are visible and manageable.

Q: Why do certificate outages happen so often in large environments?

A: Certificate outages usually come from manual tracking, fragmented ownership, and renewal work that does not scale with certificate volume. As lifecycles shorten, a small miss can become a production outage because trust expiry is both time-sensitive and operationally brittle.

Q: What is the difference between PKI hygiene and machine identity governance?

A: PKI hygiene focuses on keeping certificates valid and technically functional, while machine identity governance covers ownership, policy, lifecycle automation, and risk management. The second is broader because it addresses how trust is created, maintained, and revoked across the environment.

Q: When should organisations modernise PKI instead of keeping legacy processes?

A: Modernisation should move up the priority list when certificate counts are high, lifecycles are shrinking, manual handling is common, or outages are already appearing. At that point, delaying automation increases both security risk and operational cost.

Technical breakdown

Why certificate sprawl becomes an NHI governance problem

Internal certificates are a form of non-human identity because they authenticate services, workloads, and devices without a human in the loop. The control problem emerges when certificates are issued across on-prem, cloud, and hybrid environments but tracked in spreadsheets, tickets, or tribal knowledge. At that point, ownership, rotation, and revocation break down. The result is not only risk of expiry, but also blind spots around where trust actually exists. In mature programmes, certificate governance is tied to inventory, lifecycle automation, and policy enforcement, not treated as an isolated PKI function.

Practical implication: Map certificates to owners and services, then automate inventory and lifecycle controls before renewal failures become outages.

How short-lived TLS changes the operational model

Shorter certificate validity compresses the time available to detect, renew, test, and deploy changes. That matters because renewal is no longer a periodic admin task, it is a continuous workflow that depends on discovery, orchestration, and exception handling. As validity windows shrink, the cost of manual review rises and the margin for error narrows. This is why PKI modernization often exposes hidden dependencies in build pipelines, service meshes, and device fleets. The technical issue is not just certificate expiry. It is the inability to sustain trust-state change at machine speed.

Practical implication: Treat renewal as an automated pipeline with monitoring and rollback, not a calendar reminder.

Why weak certificate management looks like an identity compromise

Certificate theft, mis-issuance, or compromise gives an attacker a trusted identity token that can be used to impersonate services or intercept traffic. That makes PKI failure modes closer to identity compromise than to ordinary IT misconfiguration. If a private key is exposed, the attacker does not need to bypass encryption. They inherit the trust relationship itself. This is why certificate governance must be integrated with secrets handling, privileged access controls, and incident response. A certificate is not just cryptography. It is an access mechanism with blast radius.

Practical implication: Include certificate compromise in identity incident response playbooks and treat private keys as high-value secrets.

Threat narrative

Attacker objective: The attacker aims to inherit a trusted machine identity and use it to impersonate systems, intercept traffic, or gain unauthorized access.

1. Entry occurs when a private key, weakly managed certificate, or misconfigured trust chain is exposed through manual operations or insecure storage.
2. Escalation follows when the attacker uses the trusted certificate to impersonate a service, intercept communications, or authenticate as a legitimate machine identity.
3. Impact is unauthorized access or interception that bypasses normal security checks because the trust relationship itself has been compromised.

Breaches seen in the wild

• Sisense breach — unauthorized GitLab access led to exfiltration of access tokens, API keys and certificates.
• Cisco DevHub NHI breach — IntelBroker exploited exposed Cisco credentials, API tokens and keys in DevHub.

Read our 52 NHI Breaches Analysis report for a comprehensive view of breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Certificate sprawl has become a machine identity governance failure, not a tooling inconvenience. When organisations manage more than 114,000 internal certificates with only a handful of dedicated staff, the governance model itself is under strain. The practical issue is that certificates are often spread across teams, environments, and platforms with no single source of truth. Practitioners should treat certificate inventory and ownership as core identity controls, not as infrastructure housekeeping.

Shorter certificate lifecycles expose the fragility of manual renewal processes. The more often certificates expire, the more renewal becomes a continuous control function rather than an occasional maintenance event. Manual handling does not scale into that model because it increases the chance of missed renewals, inconsistent policy enforcement, and emergency changes. Practitioners should automate renewal workflows and test them like any other production dependency.

PKI failure is identity failure because trust relationships are the asset attackers want. When a private key or certificate is stolen, the attacker is not exploiting encryption, they are exploiting the authentication layer. That changes the incident profile from system outage to impersonation and unauthorized access. Practitioners should include certificate compromise in identity threat models and incident playbooks.

PKI modernization is now a governance decision, not a future architecture project. The combination of rising certificate volume, shorter validity periods, and compliance pressure means delay compounds risk. Organisations that keep PKI as a siloed engineering function will keep paying for it in outages and emergency work. Practitioners should move certificate policy, automation, and reporting into identity governance rather than treating them as separate concerns.

From our research:

• 69% of organisations now have more machine identities than human ones, according to Critical Gaps in Machine Identity Management.
• 57% of organisations lack a complete inventory of their machine identities, which means governance often starts from incomplete visibility rather than policy.
• For the lifecycle angle, read Ultimate Guide to NHIs for how inventory, rotation, and offboarding fit into a workable control model.

What this signals

Certificate governance will increasingly be judged by inventory quality, not renewal speed. As certificate lifecycles shorten, organisations that cannot answer where a certificate is deployed, who owns it, and how it is rotated will keep inheriting avoidable outage risk. Practitioners should prepare for PKI reporting to become part of identity governance dashboards, not an infrastructure-only metric.

With 67% of organisations still relying heavily on static credentials despite the risks they pose to agentic AI deployments, the broader lesson is that identity programmes tend to lag the systems they are asked to secure. That pattern will repeat in PKI unless teams automate lifecycle management and link certificate control to privileged access review.

Identity blast radius is the right concept for PKI risk. A certificate compromise can propagate trust across services, pipelines, and devices far beyond the original failure point. That means teams should assess PKI not only for uptime, but for how much authenticated trust a single key can expose across the environment.

For practitioners

• Build a complete certificate inventory Establish a system of record for internal certificates, private certificate authorities, and service owners across on-prem, cloud, and hybrid environments. Include issuance source, expiry date, key location, and business owner so renewal and revocation can be managed consistently.
• Automate renewal and rotation workflows Replace manual renewal tasks with policy-driven automation that tests, renews, deploys, and verifies certificates before expiry. Prioritise workloads with short validity windows and production services that cannot tolerate downtime.
• Treat private keys as high-value secrets Store private keys in controlled secret management systems, restrict access to the smallest possible set of identities, and include certificate compromise in incident response playbooks. Align handling with privileged access and secrets governance standards.
• Re-evaluate PKI ownership and staffing Review whether PKI is owned as a shared identity control or left to ad hoc infrastructure administration. The operational load described in the research suggests that certificate governance needs dedicated accountability, not occasional support.

Key takeaways

• Certificate failure is an identity governance problem because trust, ownership, and lifecycle control determine whether certificates remain safe to use.
• The scale mismatch is now operationally clear, with large certificate populations and small PKI teams creating avoidable exposure to expiry and compromise.
• Practitioners should automate certificate inventory, renewal, and incident handling before shorter lifecycles turn routine maintenance into recurring outages.

Key terms

• Certificate lifecycle management: Certificate lifecycle management is the process of issuing, tracking, renewing, rotating, and revoking certificates across their usable life. In practice, it is a machine identity control because certificates authenticate systems and services, and failures in renewal or revocation can create both outages and security exposure.
• Private certificate authority: A private certificate authority issues certificates inside an organisation rather than for the public internet. It is used to establish trust for internal applications, workloads, devices, and service-to-service communication, which means its governance directly affects internal identity assurance and operational resilience.
• Identity blast radius: Identity blast radius is the amount of access, trust, or system reach that a compromised identity can influence. For certificates and other non-human identities, it describes how far a stolen key or misissued certificate can propagate across systems before controls stop it.

Deepen your knowledge

PKI lifecycle governance is a core topic in our NHI Foundation Level course, the industry's only accredited NHI security programme. If your team is dealing with certificate sprawl, it is a practical place to start.

This post draws on content published by CyberArk: The hidden cost of PKI and why certificate failures are not just an IT problem. Read the original.