Guide
Open redirect parameter reflection
How StackSiren Deep Scan detects this issue and how to fix it. Severity typically medium.
Why it matters
Open redirect parameter reflection is a common finding on vibe-coded and AI-built apps that ship client bundles, shared backends or platform defaults without a security pass.
StackSiren reports this from read-only checks (GET, HEAD or OPTIONS only). It does not exploit the issue.
How to fix it
Only allow redirects to same-origin relative paths. Reject absolute URLs, protocol-relative URLs (//), and backslash tricks. Validate the next/return/redirect/url/continue parameter server-side.
How StackSiren Deep Scan checks
Deep Scan runs only on hosts you have verified you own (DNS TXT or /.well-known file) and consented to test. Findings include a short evidence string; secret values are masked.
See the Acceptable Use Policy and Active scanning terms for what Deep Scan is and is not.