CORS for PHP
medium4 checks
CORS decides which origins may read your API responses. A wildcard turns an authenticated API into a public one.
What PHP 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
- 1Replace wildcards with an explicit allowlist
- 2Validate Origin before echoing it and reject unknown origins early
PHP context
Server-side scripting runtime used by most CMS and many custom apps.
Runtime CVEs are pre-auth and application-independent (PHP2Shell CVE-2026-109618/109619). Keep PHP on a supported, patched branch.