Look for secrets stored outside a vault, repeated use of the same token across runners and repositories, and identities that can publish, deploy or read from multiple environments. Those signals show that the NHI estate has grown faster than governance, which is exactly the condition attackers exploit in CI/CD compromise campaigns.
How machine identity sprawl becomes a supply chain problem
machine identity sprawl turns into supply chain risk when the same credentials, tokens, certificates, or service accounts start bridging build systems, repositories, deployers, and runtime environments. At that point, one weak identity path can be reused to tamper with code, signing, artifacts, or release workflows, which is why the issue matters even before any obvious compromise is visible.
A practical way to think about it is that the identity estate has stopped being bounded by application function and started acting like a distribution layer for trust. If a machine identity can both read source, publish artifacts, and deploy to production, it is no longer a narrow access mechanism, it is part of the software delivery chain itself.
Repeated credentials across runners, repositories, and environments are especially dangerous because they collapse separation between stages that should fail independently. When the same token or secret can move from a low-trust workspace into a higher-trust publishing or deployment path, attackers do not need to defeat multiple controls, they only need one reusable identity path. That is the core pattern highlighted in CI/CD Pipeline Identity Security Guide and in Ultimate Guide to NHIs, Key Challenges and Risks.
What to look for in a growing blast radius
The clearest warning sign is when machine identities are no longer tied to a single purpose. A deploy token used in multiple repositories, a service account that reads from one environment and writes to another, or a publishing credential shared across runners all indicate that trust has been widened without matching governance. The same pattern appears in broader non-human identity guidance such as Service Account Security Guide and Cloud Workload Identity Guide.
Another sign is secret placement. If secrets live in source code, CI variables, runner disk, image layers, build logs, or ad hoc config files instead of a controlled vault or equivalent lifecycle process, you are looking at identity sprawl plus secret sprawl. That combination means compromise can begin anywhere the secret is copied, not just where it is officially provisioned. For certificates and long-lived cryptographic material, the same concern is captured in Machine Identity, PKI and Certificate Lifecycle Guide.
Scale also changes the signal. When teams cannot answer who owns an identity, when it should expire, or which pipeline step actually needs it, governance is behind deployment reality. That is often the point where machine identity management stops being an operational convenience and starts becoming a supply chain exposure. The ownership and lifecycle angle is covered well in NHI Ownership and Accountability Guide and Guide to NHI Rotation Challenges.
Why supply chain attackers care about this pattern
Supply chain attackers favor machine identity sprawl because it gives them trusted paths into tooling that already has publishing authority. If they can steal a token, abuse a runner credential, or inherit excessive permissions, they can stage malicious code, alter dependencies, sign or publish artifacts, or move laterally into deployment systems. In that scenario, the identity compromise is not separate from the supply chain attack, it is the access path that makes the attack feasible.
This is why secrets exposure in development tools is not just a hygiene issue. A leaked publishing token or repository credential can become an immediate release-path compromise, especially when the same credential is reused across projects or environments. The same logic appears in Secrets in VS Code extensions 2025 and Top 10 NHI Issues, where token exposure and credential reuse create direct downstream risk.
Risk and Threat Considerations
Machine identity sprawl increases the chance that a single compromised token, certificate, or service account can cross trust boundaries and reach build, package, or deployment systems. The risk is not only theft, but reuse: once an identity can operate in multiple environments, attackers can pivot from a low-value foothold into trusted release activity.
Failure mechanism: Long-lived or reused machine credentials remain valid across runners, repositories, or environments, so a compromise in one place can be replayed wherever the same identity is accepted.
Impact: Attackers can tamper with source, artifacts, or deployments, which turns an identity problem into a software supply chain compromise.
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 and MITRE ATT&CK address the attack and risk surface, while NIST SP 800-53 Rev 5, SLSA and CIS Controls v8 set the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-02 — Secret Leakage | Secrets outside vaults directly create the machine identity exposure described. |
| NHI-07 — Long-Lived Secrets | Reusable tokens across runners and repos create the sprawl and replay risk discussed. | |
| NHI-05 — Overprivileged NHI | Publish, deploy, and read access across environments reflects excessive machine privilege. | |
| Recommendation — Move machine secrets into controlled storage and eliminate source, log, and runner leakage. Replace long-lived machine credentials with short-lived, tightly scoped alternatives. Reduce each machine identity to the minimum permissions needed for one bounded task. | ||
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | Rotation and lifecycle control for secrets and tokens is central to the risk. |
| Recommendation — Enforce rotation, revocation, and expiry for machine authenticators and secrets. | ||
| SLSA | Supply Chain Levels for Software Artifacts | The question concerns software supply chain integrity and trust boundaries. |
| Recommendation — Harden build provenance and separate signing, publishing, and deployment authority. | ||
| CIS Controls v8 | CIS-5 — Account Management | Machine identity sprawl is fundamentally an account and access governance issue. |
| Recommendation — Inventory machine identities and remove unused or excessive access paths. | ||
| MITRE ATT&CK | T1552 — Unsecured Credentials | The question centers on exposed or poorly protected machine secrets being abused. |
| Recommendation — Hunt for exposed credentials and revoke any that could reach build or release systems. | ||
Practitioner Guidance
What to verify: Confirm whether every machine identity has a single documented owner, a bounded purpose, and a clearly defined expiry or rotation path. If a credential can both publish and deploy, treat that as a design flaw until proven otherwise.
Decision rule: If the same secret is present in more than one runner, repository, or environment, prioritize segregation and rotation before you optimize convenience. Shared machine access is often the strongest signal that governance has fallen behind delivery speed.
What good looks like: Build, sign, publish, and deploy functions should be separated by distinct identities with minimal permissions, short-lived credentials where possible, and observable issuance and usage. When that separation is real, compromise in one step does not automatically give an attacker release authority.
Practitioner takeaway: The moment a machine identity can move trust from code to package to production, you should treat it as a supply chain control point, not just an access credential.
Related resources from NHI Mgmt Group
- How do software supply chain controls intersect with machine identity risk?
- What are the signs that a React dependency chain is becoming a supply chain risk?
- What are the signs that supply chain risk is becoming a security problem in pharmaceutical environments?
- What are the signs that cloud supply chain risk is becoming an access problem instead of a procurement problem?
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Reviewed and updated by the NHIMG editorial team on October 6, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org