They create supply chain risk because they often grant valid downstream access without requiring a human login. If a secret is embedded in code, shared with a vendor, or copied into a pipeline, it can be reused silently until someone revokes it. The real danger is delegated trust that outlives the original purpose.
Why Service Accounts and API Keys Turn Small Integrations Into Supply Chain Risk
Service accounts and API keys become supply chain risk because they are often designed for convenience, not containment. A token that works in CI/CD, a vendor integration, or an automation script can quietly outlive the task it was meant to serve. That means one copied secret can become a reusable trust path across code, pipelines, chat tools, and third-party systems. The problem is not just exposure, it is durable delegated access.
This is why secret sprawl matters so much in modern software delivery. GitGuardian’s State of Secrets Sprawl 2026 found 64% of valid secrets leaked in 2022 are still valid and exploitable today, which shows how often detection fails without revocation. NHIMG breach analysis has repeatedly shown the same pattern in incidents such as the Shai Hulud npm malware campaign and Reviewdog GitHub Action supply chain attack: once a secret is copied into an ecosystem, it can be reused far beyond the original developer or repository. In practice, many security teams discover this only after a vendor, pipeline, or automation path has already inherited the trust.
How the Risk Spreads Across Code, Pipelines, and Vendors
A service account or API key becomes high-risk when it is treated as a stable identity instead of a short-lived capability. In supply chains, that credential may be embedded in source code, injected into a build runner, shared with a SaaS vendor, or consumed by an AI tool. Each handoff creates another place where the secret can be copied, logged, cached, or stolen. Current guidance from OWASP Non-Human Identity Top 10 and the NIST Cybersecurity Framework 2.0 points toward least privilege, lifecycle control, and continuous monitoring, but the operational gap is often secret reuse across environments.
Practitioners should think in terms of blast radius, not just authentication. A single key can often:
- authenticate a workload without any human login or step-up check
- persist across CI jobs, containers, and ephemeral runners if not rotated
- grant downstream access to storage, messaging, SaaS APIs, or cloud control planes
- remain valid after a code branch is deleted or a vendor engagement ends
This matters because attackers do not need perfect persistence if the secret itself remains accepted. The NHIMG 52 NHI Breaches Analysis and DeepSeek breach both illustrate how exposed credentials can become long-lived access paths once they enter shared tooling or public artifacts. These controls tend to break down when secrets are reused across third-party build systems and the owning team cannot prove where the credential is stored or how many copies exist.
Where the Standard Answer Breaks Down
Tighter secret controls often increase delivery overhead, requiring organisations to balance speed against containment. That tradeoff becomes most visible in legacy systems, partner integrations, and automation stacks that were built around static credentials. In those environments, simply shortening passwords or rotating keys more often can create outages if the application cannot fetch replacement secrets reliably.
Best practice is evolving toward narrower alternatives, but there is no universal standard for this yet. Stronger patterns include workload identity, just-in-time issuance, and ephemeral secrets with short TTLs, especially where a service account only needs to prove what it is doing right now. For example, a workload can authenticate with cryptographic identity, then receive a scoped token for a single action instead of carrying a standing secret. That is materially different from handing every pipeline a reusable API key.
NHIMG’s guidance in the Ultimate Guide to NHIs — What are Non-Human Identities and the Guide to the Secret Sprawl Challenge is to design for revocation first, then access. That means identifying every place a secret can surface, limiting who or what can mint it, and treating every static token as a liability to be replaced, not merely monitored.
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 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 | Secret rotation and lifecycle control are central to reducing exposed NHI blast radius. |
| NIST CSF 2.0 | PR.AC-4 | Least-privilege access management directly limits what leaked keys can reach. |
| NIST AI RMF | Governance and accountability are needed when autonomous tooling can consume secrets at runtime. |
Inventory service-account secrets, set TTLs, and automate rotation and revocation everywhere they are consumed.
Related resources from NHI Mgmt Group
- What problem does ownership attribution solve for service accounts and API keys?
- Why do service accounts and API keys create more risk than many human accounts?
- Why do API keys and service accounts create more risk than traditional user accounts?
- Why do service accounts and API keys create more hidden risk than user accounts?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on June 3, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
