Why security scanning tools miss the threats that actually matter
Your CI/CD pipeline runs SAST. Your pre-production environment runs DAST. You're scanning dependencies with SCA. You're still vulnerable.
The problem isn't the tools - it's understanding what each one actually does, and more importantly, what it doesn't.
What each tool actually catches
SAST (Static Application Security Testing) analyzes source code before runtime. It finds SQL injection, hardcoded credentials, insecure logic. It's fast, runs early, and catches issues when they're cheap to fix. But it can't see what happens when code actually runs, and it generates false positives that teams learn to ignore.
DAST (Dynamic Application Security Testing) attacks running applications from the outside, like a real attacker would. It finds authentication bypass, session management flaws, runtime configuration issues. But it misses code paths that aren't exercised during testing, and it runs late in the cycle when fixes are expensive.
SCA (Software Composition Analysis) scans third-party dependencies for known CVEs and license risks. It's accurate and fast because it's checking against documented vulnerabilities. But it only knows about published CVEs - zero-days and custom code flaws are invisible.
The combination problem
Most applications are now majority open-source code, making SCA non-negotiable. But SCA won't catch the business logic flaw in your custom authentication handler. SAST will flag that handler but might miss the vulnerable library it calls. DAST might find both - if your test coverage exercises that code path.
History suggests the winning approach isn't picking one tool. It's understanding the gaps between them.
What this means in practice
For GitHub Actions and Jenkins pipelines, the integration pattern matters more than the tool choice. SAST should block PRs on high-severity findings. SCA should run on every dependency update. DAST should run in staging, not production.
The harder problem is alert fatigue. Teams receiving hundreds of SAST findings learn to ignore them. Configure thresholds carefully. Tune for your codebase. Accept that false positives are the cost of early detection.
Notably, no scanning tool replaces penetration testing for business logic flaws and complex attack chains. The tools find known patterns. Skilled attackers find unknown ones.
Three things to watch
SBOM momentum: Software Bill of Materials is becoming a procurement requirement, making SCA tooling table stakes for government and enterprise contracts.
IAST and RASP: Interactive (IAST) and Runtime (RASP) testing are emerging as the middle ground between SAST and DAST, but adoption remains limited outside large enterprises.
Tool consolidation: Modern SAST tools increasingly bundle SCA. The vendors know you need both.
The trade-off remains: comprehensive coverage versus alert fatigue. Pick your tools based on what actually ships, not what sounds impressive in vendor pitches.