Teams should separate configuration from secret values. Keep the configuration file in source control, replace sensitive values with references, and resolve those references at runtime. That preserves collaboration, makes reviews and pull requests practical, and avoids plaintext secrets in .env files or README instructions. The result is a reproducible workflow that is easier to maintain across local development and production.
Separate configuration from secret material
The practical rule is to treat configuration as code and secrets as runtime inputs. Put non-sensitive settings in source control, but replace passwords, API keys, tokens, and certificates with references that are resolved by the application or deployment platform when it starts. That keeps reviewable configuration versioned without turning the repository into a secret store.
This split matters because source control is optimized for collaboration, traceability, and rollback, not for protecting high-value credentials. A checked-in secret tends to spread quickly through clones, forks, logs, backups, build outputs, and developer tooling, which is why teams should manage configuration and secret handling as different workflows.
Use runtime resolution instead of hardcoded values
Runtime resolution lets the same application package move across environments without rewriting files or exposing sensitive values in .env files, README examples, or pull requests. The reference can point to a vault path, environment binding, injected file, or secret manager lookup, but the sensitive value itself should only appear where the execution environment can fetch it securely.
That approach also preserves reproducibility. Developers can share the same configuration shape across local, test, and production environments while each environment supplies its own secret values at deploy time. The important design choice is that the application should depend on a secret source, not on a literal secret sitting in the repository.
Design the workflow around rotation, review, and blast radius
A safe configuration pattern is not just about hiding values, it is about reducing how long a secret remains valid and how far it can travel if exposed. Teams should prefer short-lived or renewable secret values where possible, and they should structure deployment access so that configuration changes can be reviewed without giving everyone direct visibility into the underlying credentials.
When a secret is exposed in source control, the response is usually rotation first, investigation second. That ordering reflects the blast-radius problem: once a credential is copied into a repository, assume it may already be replicated beyond the original team boundary, even if the repository is private.
Risk and Threat Considerations
The main risk is that source control turns a single mistake into durable, widely replicated exposure. Hardcoded secrets can be harvested by insiders, external attackers, dependency scanners, CI jobs, backups, and repository mirrors, and they can remain usable long after the original commit is forgotten.
Failure mechanism: Secrets are embedded in code, sample files, or configuration templates, then propagated through commits, forks, build artifacts, and logs where they can be discovered and reused before the team notices.
Impact: Attackers or unauthorized users can authenticate to downstream systems, move from one environment to another, and use the exposed values for data access, service abuse, or further compromise until the secret is revoked and replaced.
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 OWASP API Security Top 10 address the attack and risk surface, while CIS Controls v8 and NIST SP 800-53 Rev 5 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 in source control directly create secret leakage risk. |
| NHI-07 — Long-Lived Secrets | Checked-in secrets often persist longer than intended and widen exposure. | |
| Recommendation — Store secrets outside source control and resolve them at runtime. Prefer short-lived or renewable secrets and rotate exposed values immediately. | ||
| CIS Controls v8 | CIS-5 — Account Management | Managing access values separately reduces unsafe credential exposure and reuse. |
| Recommendation — Separate secret handling from code and restrict who can retrieve production credentials. | ||
| OWASP API Security Top 10 | API2 — Broken Authentication | Exposed API keys and tokens undermine authentication if stored in code. |
| Recommendation — Keep API credentials out of repositories and inject them only at runtime. | ||
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | Secret values require lifecycle control, including storage, rotation, and revocation. |
| Recommendation — Manage secret lifecycle centrally and rotate any credential that may have been exposed. | ||
Practitioner Guidance
What to verify: Make sure every sensitive setting has a non-secret placeholder in source control and a documented runtime source of truth. If a reviewer can recover a usable credential from the repository, example file, or pipeline definition, the pattern is not safe yet.
Decision rule: If the value grants access, treat it as secret material and remove it from the repo path entirely; if it only changes behavior and has no security value, it can remain in versioned configuration. That distinction keeps teams from over-securing ordinary settings while still closing the real exposure path.
Practitioner takeaway: The goal is not to hide configuration, it is to keep secrets out of the collaboration layer and let only the runtime environment resolve them.
Related resources from NHI Mgmt Group
- How should Android teams manage environment-specific configuration without exposing release-time secrets in the app package?
- How should security teams manage LLM credentials in agentic environments without exposing secrets to applications and agents?
- How should teams manage secrets in GitOps workflows without breaking declarative control?
- How should security teams manage secrets in Helm charts without exposing sensitive data in Git or cluster manifests?
Deepen Your Knowledge
Reviewed and updated by the NHIMG editorial team on September 26, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org
