SAST, DAST, and PR security review are often grouped together, but they answer different questions.
SAST asks: does the code match a risky pattern?
DAST asks: does the running application behave unsafely?
PR security review asks: did this change introduce exploitable risk before it merges?
Teams need all three at different moments. The problem starts when one workflow is expected to cover every kind of vulnerability.
SAST
Static application security testing (SAST) scans source code without running the application.
SAST is useful for:
Known vulnerability categories.
CI policy checks.
Language and framework-specific rules.
Secrets and unsafe APIs.
Broad repository coverage.
SAST is weaker when the issue depends on product intent, multi-step auth flow, or whether a path is reachable by an attacker.
DAST
Dynamic application security testing (DAST) probes a running application.
DAST is useful for:
Runtime misconfiguration.
Exposed endpoints.
Authentication and session issues.
Known web vulnerability classes.
Validating behavior in a deployed environment.
DAST is weaker when the vulnerable path is hard to reach, requires specific business state, or is in code that the tested environment does not expose.
PR security review
PR security review looks at the code change while the author and reviewers are still deciding whether to merge it.
It is useful for:
Broken access control.
Business logic flaws.
Prompt injection and AI agent behavior.
Risky dependency or GitHub Actions changes.
IaC permissions and deployment risk.
Explaining exactly what the author should fix.
This is where Hacktron Review fits. It reviews pull requests for exploitable vulnerabilities and posts findings inline in GitHub.
How SAST, DAST, and PR review compare
| Workflow | Best at | Weakness | Best timing |
|---|---|---|---|
| SAST | Known code patterns | Context and reachability | CI and periodic scans |
| DAST | Runtime behavior | Code paths that tests cannot reach | Staging and production-like environments |
| PR review | Exploitability in a code change | Needs repository context | Before merge |
What to use first
If your current issue is “we have no security coverage,” start with SAST and dependency scanning.
If your issue is “we find bugs too late,” add PR security review.
If your issue is “we need proof the running app is exploitable,” add DAST or whitebox validation.
Hacktron covers PR security review. It catches risky code before merge, then escalates high-risk paths into deeper validation when needed.