Stop SSRF in a link-preview fetcher

Not solved

The server fetches any URL a user pastes. Its allow-list is a substring check. Make it impossible to reach internal hosts.

Level
Practitioner
Estimated time
~25 min
Points
0/80 pts
Questions
0/0 answered
OWASP
A01:2025
CWE
CWE-918
preview.js
Test results

Run the tests to check your code. It runs on the server in an isolated sandbox with no network access.