Medium · published August 5, 2026
Pixelfed's SearchController (behind the auth middleware) accepts a URL via its remote-search parameters and fetches it server-side through ActivityPubFetchService, whose validateUrl only blocks the literal hosts 127.0.0.1, localhost, and ::1 and requires https, without checking the resolved IP against private, internal, or link-local ranges (e.g. 169.254.169.254).