Because a secret is a non-human identity with permissions, scope, and lifetime, and code repositories replicate it faster than teams can manually track it. Once exposed, the credential can be copied into builds, logs, and forks. That makes access control, rotation, and ownership central to the response.
Why This Matters for Security Teams
Secrets in source code are not just a leakage issue, they are an identity governance issue. A stored token, API key, or certificate can outlive the workload it was issued for, get copied into forks and build logs, and persist long after offboarding or app decommissioning. That makes secrets part of the NHI attack surface, with ownership, rotation, and blast radius becoming the real control questions.
NHIMG research shows how widespread the problem is: 62% of secrets are duplicated and stored in multiple locations in The 2025 State of NHIs and Secrets in Cybersecurity. That duplication turns a single mistake into a distributed governance failure. Current guidance from OWASP Non-Human Identity Top 10 and NIST Cybersecurity Framework 2.0 points to the same outcome: treat secrets as managed identities, not static text in code.
In practice, many security teams discover the governance gap only after a secret has already been copied into a CI pipeline, a ticket, or a public fork.
How It Works in Practice
The core failure is that source control makes a secret easy to replicate but hard to govern. Once a credential is embedded in code, it becomes visible to developers, bots, scanners, CI jobs, release artifacts, and sometimes third parties. That breaks the normal lifecycle model because the secret now has multiple owners in effect, even if only one owner exists on paper. A practical NHI control model needs to track where the secret lives, who can use it, what it authorises, and when it expires.
For that reason, good practice is shifting toward ephemeral credentials, short TTLs, and workload identity. Instead of checking a long-lived secret into a repository, teams should issue a just-in-time credential at runtime, bind it to the workload, and revoke it on completion. This is especially important for autonomous systems and CI/CD jobs, where the identity is a machine or agent that can act quickly and repeatedly. See the Guide to the Secret Sprawl Challenge and the Shai Hulud npm malware campaign for examples of how code-adjacent exposure turns into wider compromise.
- Use secret scanning in pre-commit, pull request, and CI stages, but do not stop there.
- Replace hardcoded secrets with vault-backed retrieval and short-lived tokens.
- Assign explicit owners for each NHI secret and define rotation SLAs.
- Restrict where secrets can be injected, logged, or exported during builds.
- Prefer workload identity over shared static credentials wherever possible.
Where implementation is mature, teams also align secret handling to least privilege and zero standing privilege, so access exists only for the minimum time needed. These controls tend to break down in legacy batch systems and third-party integrations because those environments still depend on shared, long-lived credentials.
Common Variations and Edge Cases
Tighter secret controls often increase operational overhead, requiring organisations to balance faster delivery against stronger identity governance. That tradeoff is real, especially when multiple teams share the same deployment pipeline or when vendors require static credentials. There is no universal standard for every migration path yet, so current guidance suggests prioritising the highest-risk secrets first: production tokens, signing keys, and credentials with broad scope.
Edge cases appear when secrets are not directly in code but are still effectively exposed through adjacent systems. Comments, sample files, test fixtures, ticketing systems, and documentation can all become shadow repositories. The risk is amplified when teams lack full visibility into connected services, which is why breach analysis in the 52 NHI Breaches Analysis remains useful for pattern recognition. For governance teams, the lesson is to treat all copyable secret material as part of the same identity estate, not separate hygiene tasks.
For standards alignment, this is consistent with the governance intent of NIST Cybersecurity Framework 2.0 and OWASP Non-Human Identity Top 10, but best practice is still evolving around how to measure secret sprawl across repos, vaults, and pipelines. In mixed environments, the control can fail when a secret is valid across multiple apps, because revocation may break production before ownership has been untangled.
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 exposure are central to NHI-03 governance. |
| NIST CSF 2.0 | PR.AC-4 | Least-privilege access limits blast radius if a code secret leaks. |
| NIST AI RMF | AI RMF helps govern autonomous workloads that consume secrets. |
Assign accountability for secret use in autonomous workflows and evaluate runtime access decisions.
