Snyk

Snyk

Snyk is a developer security platform. It finds and fixes vulnerabilities in your code (SAST), open source dependencies (SCA), container images, and infrastructure as code (IaC).

When to Use

• Dependency Checking: "Does lodash have a vulnerability?" (SCA).
• Container Security: Scanning your Dockerfile base image for CVEs.
• IDE Integration: Real-time feedback in VS Code / IntelliJ while you code.

Quick Start

# Install CLI
npm install -g snyk

# Authenticate
snyk auth

# Test dependencies
snyk test

# Monitor (Continuous watching for new vulns)
snyk monitor

Core Concepts

Vulnerability Database

Snyk maintains a proprietary DB (Intel) that often alerts faster than the public NVD.

Fix PRs

Snyk can automatically open a Pull Request to upgrade a vulnerable dependency to the patched version.

Reachability Analysis

Determines if a vulnerable function in a library is actually called by your code. prioritization.

Best Practices (2025)

Do:

• Enable Snyk in CI: Fail the build if High or Critical vulnerabilities are introduced.
• Use Snyk Code: For SAST (finding bugs in your own code).
• Prioritize Reachable Vulns: Don't waste time patching libraries you don't even use the dangerous part of.

Don't:

• Don't Ignore Low Severity: Bulk triage them, but don't let them accumulate forever ("Death by a thousand cuts").
• Don't blindly upgrade: Verify breaking changes. Snyk usually warns about this.

Troubleshooting

Error	Cause	Solution
Auth Failed	Token expired/missing.	Run snyk auth again or set SNYK_TOKEN env var.
Too many issues	Legacy codebase.	Use .snyk file to ignore known/wont-fix issues or set a baseline.

References

• Snyk Documentation
• Snyk CLI