CORS for SolidJS

medium4 checks

CORS decides which origins may read your API responses. A wildcard turns an authenticated API into a public one.

What SolidJS must have

  • Access-Control-Allow-Origin limited to known origins
  • No wildcard combined with credentials
  • No reflection of arbitrary Origin headers
  • Preflight responses only allow the methods actually used

How to fix it

  1. 1Replace wildcards with an explicit allowlist
  2. 2Validate Origin before echoing it and reject unknown origins early

SolidJS context

Fine-grained reactive UI library compiling to direct DOM operations.

innerHTML prop is the escape hatch; treat it as a sink and sanitise input.