EXPOSURE Langfuse
SEVERITY MEDIUM
PROBE GET :3000/api/public/health
Is your Langfuse exposed?
Tracing dashboard reachable: your LLM prompts, outputs, and user data on display.
Scan a host you own → Fix card Census
Why it matters
Your LLM observability stack is publicly reachable — Langfuse stores prompts, completions, tool calls, and agent session state that can contain customer data and secrets. If the sign-up page is open, anyone can create an account and start reading those traces.
How common is it?
1,558 Langfuse instances are reachable in the Shodan index. Fingerprint match, not a verified zero-auth count · src: Shodan count · `http.html:"LangfuseIcon"` · 2026-08
Counts are population-level, from third-party indexes and my own honeypots. I never scan the internet and this page makes no claim about any specific host.
Fix it
The full walkthrough lives on the fix card, kept current in one place: