What pre-commit Hooks Actually Do (and Don’t Do)?
The pre-commit framework is commonly used to enforce local validations before code is committed to a Git repository. It can run checks such as linters, formatters, and even custom scripts to catch issues like hardcoded secrets. But here’s the catch: hooks run only on the developer’s machine. That means if someone disables the hook, fails to install it, or intentionally skips it, the entire protection layer is compromised.
Git’s native pre-commit hook is not enforced server-side. There’s no guarantee that all team members have it set up or that they use it correctly. Without centralized enforcement, these hooks become optional guardrails rather than hard stops. In distributed teams or open-source projects, this makes them unreliable as the only line of defense.
In short, pre-commit hooks do help reduce security risks locally, but they’re not enough on their own. The term “pre-commit” gets thrown around a lot, but unless it’s tied to a broader enforcement strategy, it’s more like a suggestion than a control.
How Developers Bypass git pre commit hook Checks
There are plenty of real-world ways developers bypass git pre-commit hook validations, whether intentionally or not:
- –no-verify flag: This one-liner bypasses all checks:
git commit -m “hotfix” –no-verify
It’s often used under pressure, in emergencies, or just because a developer is blocked by a failing check. - Untracked config files: Secrets often hide in .env, config.yml, or settings.py files. If these files aren’t tracked or scanned by pre-commit, they’ll slip through unnoticed.
- Missing hook installation: If the team doesn’t enforce hook installation via pre-commit install or CI validation, then new team members or contributors can push code without any local checks ever running.
- Manually edited .git pre-commit hooks: Developers can even change or remove the pre-commit hook file if there’s no policy preventing it.
In short, git pre-commit hook mechanisms are easily bypassed and depend entirely on developer discipline, which doesn’t scale.
CI/CD Pipelines: Where pre-commit Stops Working
Once code leaves the local machine and enters the CI/CD pipeline, pre-commit’s control ends. Unless explicitly mirrored in the pipeline, all those validations disappear. That creates a massive blind spot.
For example, imagine a team using GitHub Actions or GitLab CI to deploy automatically on merge. If someone bypasses pre commit locally and pushes secrets, the pipeline will happily build and deploy those secrets to staging or even production.
Without pipeline-level secret detection or validation steps, pre-commit protections are worthless once code hits git push.
It’s common to see CI workflows that run tests and deploy code without checking if the git pre-commit hook validations passed in the first place. This disconnect is where security risks grow fast.
Enforcing Secret Scanning and Security in CI/CD
To close these gaps, secret detection and security controls must be baked into CI/CD pipelines. Here’s how:
- Use server-side scanning tools: Integrated tools like git leaks, truffleHog, or detect-secrets directly in the pipeline. They scan every commit or PR for secrets.
- API-based scanning: Some platforms offer API access to scan repos asynchronously or on demand. This allows external validation without slowing down the pipeline.
- Fail builds on detections: Set up policies to fail builds or reject merges when secrets or misconfigurations are detected.
- Pre-merge enforcement: Use GitHub/GitLab branch protection rules to require that secrets scanning passes before merge.
- Integration with Xygeni: Detects exposed secrets, misconfigurations, and vulnerable dependencies directly in the pipeline, blocking unsafe merges automatically. It provides policy enforcement at build time and integrates seamlessly with popular CI/CD platforms.
This approach shifts validation left but keeps enforcement centralized. It also replaces weak local-only pre-commit usage with reliable, auditable workflows.
Hardening pre-commit Usage with Real Controls
If you’re using pre-commit, make it count:
- Policy-as-code: Define security policies as part of your repo using frameworks like OPA or custom YAML rules. Enforce them across teams.
- Secure templates: Use cookiecutter or custom boilerplates that include this setup and standard hooks, making secure defaults the path of least resistance.
- Pipeline enforcement: Mirror pre-commit hooks in your CI pipeline using the pre-commit run– all-files command.
- Auditable trails: Log and alert when –no-verify is used, or when a commit skips validation. Push visibility into the DevSecOps process.
- Standardize git pre-commit hook usage: Make sure the same hooks run consistently in local dev and CI to avoid security drift.
These changes don’t just make pre-commit more effective; they create a culture of proactive security enforcement.
So, Local Hooks Are Not Enough
Pre-commit hooks are useful but fragile. They depend entirely on local setup and individual discipline, and can be bypassed with a flag. In shared repositories and CI/CD workflows, they break down fast.
Real security in AppSec means implementing enforcement where it can’t be ignored: in CI/CD. Server-side secret scanning, merge-time policies, and centralized tools are key.
The git pre-commit hook is not dead weight, but it’s not a firewall either. Developers should treat it as part of a layered strategy, not the whole solution.
Tools like Xygeni help bridge the gap, enforcing policies, detecting exposed secrets in pipelines, and securing builds before they go live. Don’t rely on local hooks alone; harden your pipelines where it really matters.
