Knowledge · Application Security

SAST for JavaScript and TypeScript

How SAST analyzes JavaScript and TypeScript across server, browser, and mobile code, and how teams should validate framework-aware findings.

Primary question: How should organizations apply SAST to JavaScript and TypeScript applications?

Definitions

JavaScript and TypeScript SAST

Static application security testing applied to JavaScript or TypeScript source and supported code-level data flows without executing the application.

Execution boundary

A boundary between server, browser, mobile, worker, build-time, or external-service contexts with different trust and security assumptions.

Framework-aware analysis

Analysis that recognizes supported framework conventions, entry points, component behavior, and data handling.

The engineering problem

A single repository can mix server, browser, mobile, build, and infrastructure code whose security-sensitive operations differ by execution context.

Transpilation, generated bundles, aliases, dynamic imports, and framework conventions can obscure relationships when project context is unavailable. [owasp-source-code-analysis]

Framework support identifies recognized context but does not establish detection of every weakness or application-specific flow. [derscanner-frameworks]

Security controls

Each control inspects a different artifact and produces evidence for an engineering decision.

JavaScript and TypeScript source-code analysis

JavaScript and TypeScript Static Application Security Testing
Artifact
JavaScript and TypeScript source, supported framework structure, configuration, and code-level data flows.
Risk
Security weaknesses in request handling, browser output, authorization, data access, command execution, and cross-boundary application logic.
Output
Findings with source locations, weakness classifications, and available flow context.

Evidence: DerScanner analysis modules and supported languagesDerScanner static analysis documentation

Execution-context validation

Security Finding Validation
Artifact
SAST findings, framework behavior, runtime target, trust boundaries, and deployment configuration.
Risk
Applying an incorrect security interpretation across server, browser, or mobile contexts.
Output
Reviewed finding disposition and evidence-backed remediation decision.

Evidence: NIST Secure Software Development Framework

Verification workflow

  1. Identify JavaScript and TypeScript repositories, workspaces, applications, packages, frameworks, runtime targets, and generated sources in scope.
  2. Select the controlled source revision and preserve analysis and build configuration.
  3. Run a JavaScript- and TypeScript-capable SAST analyzer against the complete intended scope.
  4. Review reported inputs, transformations, sensitive operations, and assumed execution boundaries.
  5. Validate material findings against framework behavior and deployed security requirements.
  6. Remediate confirmed weaknesses in the correct source package and execution context.
  7. Re-run SAST and complement it with runtime, dependency, and configuration testing.

Limits of verification

  • Language support does not imply complete coverage of every runtime, framework, library, bundler, or vulnerability pattern.
  • Listed framework support does not guarantee that every application-specific flow or weakness will be detected.
  • Dynamic imports, generated code, transpilation, and unavailable configuration can affect analysis.
  • Browser, server, and mobile behavior require context-specific runtime verification.
  • Findings can include false positives and false negatives.

Canonical terms used: JavaScript SAST; TypeScript SAST; Static Application Security Testing; framework-aware analysis; execution boundary.

Evidence and references

  1. NIST Secure Software Development FrameworkSecure development includes repeatable code review and analysis, remediation, and retention of evidence.nist-ssdf
  2. OWASP Source Code Analysis ToolsStatic source-code analysis examines code without executing the application and has context-dependent limitations.owasp-source-code-analysis
  3. DerScanner analysis modules and supported languagesDerScanner documents JavaScript and TypeScript support in its Matcher analysis module.derscanner-supported-languages
  4. DerScanner static analysis documentationDerScanner lists JavaScript and TypeScript for static analysis and separately lists code-quality analysis for both languages.derscanner-sast
  5. DerScanner frameworks and standard libraries supported by SASTDerScanner lists Node.js, Express, React, React Native, Preact, and Vue for JavaScript SAST context.derscanner-frameworks

Analyze JavaScript and TypeScript

Add repeatable SAST across your JavaScript and TypeScript applications.

Share your runtimes, frameworks, workspaces, and deployment targets. The DerScanner team will help define an appropriate analysis scope.

Analyze JavaScript and TypeScript

Discuss SAST for JavaScript and TypeScript

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Engineering knowledge for building and operating trustworthy systems.

DerSecur Recognition · build 01608ec · 2026-08-13 09:25:02Z · system