Debugging CORS Origin Bugs
A practical way to inspect origin parsing, credentials, and header behavior.
Pattern
Origin matching accepts or rejects the wrong host because parsing is too loose.
warningSymptoms
- arrow_rightBrowser-only failures
- arrow_rightCredentials rejected
- arrow_rightUnexpected origin allowed
searchWhere to look
- arrow_rightOrigin parser
- arrow_rightAllowed list checks
- arrow_rightCredential headers
- arrow_rightSubdomain and suffix matching
buildCommon fixes
- arrow_rightParse origins as URLs
- arrow_rightCompare hostnames exactly where required
- arrow_rightAdd edge-case tests