SAST vs DAST vs SCA — Comparison — DevSecOps Interactive Learning

Side-by-side comparison

Dimension	SAST	DAST	SCA
What it tests	Source / bytecode patterns & data flow	Running HTTP app & config behavior	Third-party packages vs vuln DBs
When it runs	CI on commit/PR; IDE	After deploy to test env	CI on lockfile/manifest change
Coverage driver	Code paths (not runtime routes)	Crawl/OpenAPI + reachable URLs	Declared dependencies
Speed	Fast to moderate	Slower (network I/O)	Fast (metadata + matching)
False positives	Higher without tuning	Moderate (config dependent)	Lower for exact version matches
Blind spots	Runtime-only issues	Source-level API misuse	In-house code flaws

Where each fits in the pipeline

SAST DAST SCA

Decision matrix: which to use when

Toggle a focus to emphasize relevant rows (interactive).

Your need	Prefer	Rationale
Stop SQLi/XSS patterns before merge	SAST	Points to exact lines; fast in CI
React to CVEs in dependencies	SCA	Maps versions to advisories
Validate headers, cookies, WAF in staging	DAST	Observes real HTTP behavior
Enforce banned APIs company-wide	SAST	Custom rules in code
Find exposed admin routes post-deploy	DAST	Discovery against running app
License compliance reporting	SCA	BOM + policy engine

When to use all three together

Modern DevSecOps programs run SAST + SCA on every PR (fast feedback on your code and their code), and DAST on staging on a schedule or before release (validate real-world exposure). Penetration tests and threat modeling add human judgment on top—tools narrow the search space.

Correlate IDs: link SAST CWE, SCA CVE, and DAST alert URL in the same ticket system.
Share suppressions with expiry and owner so risk is tracked, not hidden.